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Lodenafil carbonate

UNII-29X84F932D, CRIS-031  

bis-(2-{4-[4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-benzenesulfonyl]piperazin-1-yl}-ethyl)carbonate

5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one. IS THE NAME OF MONOMER

398507-55-6  CAS

Cristalia (Originator)

Lodenafil is a drug belonging to a class of drugs called PDE5 inhibitor, which many other erectile dysfunction drugs such as sildenafil, tadalafil, and vardenafil also belong to. Like udenafil and avanafil it belongs to a new generation of PDE5 inhibitors.

• Sildenafil, tadalafil, vardenafil, and the newer udenafil and avanafil selectively inhibit PDE5, which is cGMP-specific and responsible for the degradation of cGMP in the corpus cavernosum. These phosphodiesterase inhibitors are used primarily as remedies for erectile dysfunction, as well as having some other medical applications such as treatment of pulmonary hypertension.

Lodenafil is formulated as a dimer, lodenafil carbonate, which breaks down in the body to form two molecules of the active drug lodenafil. This formulation has higher oral bioavailability than the parent drug.^[1]

It is manufactured by Cristália Produtos Químicos e Farmacêuticos in Brazil and sold there under the brand-name Helleva.^[2]

Helleva (Lodenafil Carbonate) is an oral PDE5 inhibitor prescribed to treat men suffering from erectile dysfunction. It operates by relaxing muscles and dilating blood vessels in the penis to increase circulation making it easier to attain and maintain an erection.

It has undergone Phase III clinical trials,^[3][4][5] but is not yet approved for use in the United States by the U.S. Food and Drug Administration.

lodenafil

………..

SYNTHESIS

WO 2002012241 OR US7148350

MONOMER synthesis

PIPERAZINE

AND

ETHYL CHLORO ACETATE

WILL GIVE

Ethyl 1-piperazinylacetate

SEE RXN 1 BELOW

Reaction 1:

Synthesis of Piperazine Ethyl Acetate

To a reaction blend containing 100 g (3 Eq, 0.515 mol, MW=194) of piperazine, 26.3 mL (1.1 Eq, 0.189 mol, MW=101, d=0.726) of triethylamine in 200 mL of isopropanol, add to a solution previously prepared of 18.4 mL (1 Eq., 0.172 mol, MW=122.55, d=1.15) of chloroacetate of ethyl in 140 mL of isopropanol under stirring, at room temperature. Keep the reaction medium under stirring, monitoring the reaction termination by means of a chromatography of the thin layer (about 2–3 hours). Add a solution of 40.6 g (0.344 mol) of succinic acid in 140 mL of isopropanol. Keep the system under stirring for about 30 minutes to assure total precipitation of the succinate salt of piperazine formed. Filter this salt and concentrate the filtrate containing the mono and dialkyled derivatives. We obtain a slightly yellowish oil, which is used in later phases without purification.

Mass obtained=33 g

GC/MS: Monoalkylated derivative 72%, and dialkylated 22%.

NEXT

Piperazine Ethyl Acetate

AND

5-(5-chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one

WILL REACT TO GIVE… 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one AS IN RXN 4 BELOW

Reaction 4:

Synthesis of 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one.

Suspend 24.6 g (60 mmol, MW=410.9) of 5-(5-chlorosulfonyl-2-etoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one in 900 mL of ethanol absolute. Under stirring and at room temperature, add at only one time, a solution containing 31.0 g (3 Eq., 180 mmol MW=172) of N-piperazine ethyl acetate (Reaction 1) dissolved in 150 mL of ethanol absolute. In an interval of 2–10 minutes, all solid is consumed, forming a clean and homogeneous solution, and after that starts the precipitation of the expected product. At the end of the reaction, which lasts 2–3 hours (monitored by chromatography of thin layer), the product is vacuum filtered and the solid is washed with two portions of 50 mL of iced absolute ethanol. 29 g are obtained (yielding=89%) from the product as a white solid of MP=165.5–166.5° C.

Reaction 7:

Intermediate 1

5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one.  IS MONOMER

please note during LAH redn  …………. the PIP CH2-C=O-O CH2 CH3     BECOMES        PIP-CH2CH2-OH

To a suspension of lithium aluminum hydride (0.74 g 2.2 Eq. MW=37.9) in 25 mL of THF, slowly add, under stirring and at room temperature, a suspension of 5.0 g (9.1 mmol, MW=546.6) of 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one in 50 mL of THF. The system is maintained under stirring, monitoring the consumption of the product by chromatography of thin layer, until the complete consumption of the starting reagent (about 5–6 hours). Slowly add water to the reaction medium and, when there is no longer release of H₂, add HCl 1M regulating pH for 7. Extract the product with 3 200 mL-portions of chloroform, dry with anhydrous sodium sulfate and vacuum concentrate the product. It is obtained 3.8 g of the product as a cream solid MP=183–187° C. yielding 83%. The same was crystallized from methanol and DMF yielding a slightly yellowish solid with melting point at 189–192° C.

note …………. the PIP CH2-C=O-O CH2 CH3 BECOMES  PIP-CH2CH2-OH

HOMODIMER CARBONATE

EXAMPLE 1B

Homodimer Carbonate of Intermediate 1—Alternative Method

A phosgene solution (3.5 g, 35 mmol) dissolved in 20 mL of toluene was added dropwise to a solution of 2.02 g (4 mmol) of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, suspended in 44 mL of toluene. The reaction mixture resulting is stirred and followed by chromatography analysis of thin layer every hour until the reagent conversion in its chloroformate was completed. When the analysis indicates the complete consumption of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, the volatile compounds of the reaction are vacuum removed (solvents and phosgene), yielding the esther chloroformate raw derivative of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one.

The raw chloroformate obtained above (4.0 mmol, 2.27 g) is dissolved in about 30 mL of dichloromethane, to which is added 2.07 g (4.1 mmol) of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, followed by the addition of 4 mL of dichloromethane containing 450 mg of triethylamine. The reaction mixture is maintained under stirring, being followed by chromatography of thin layer every hour until this indicates the end of the reaction (disappearing of chloroformate derivative). The reaction mixture is then diluted with 60 mL of dichloromethane, washed with NaCl saturated solution, after with sodium bicarbonate saturated solution and again with NaCl saturated solution. Organic phase is separated and dry with anhydrous sodium sulfate. The solvent is then evaporated to dry, yielding the dimer carbonate as a slightly yellowish solid.

This compound is re-crystallized from ethanol:DMF, yielding a pale white solid. Yielding m=3.2 g (76%)

Microanalysis: Theoretical C, (54.53%); H, (6.04%); N, (16.24%);

Obtained C, (54.45%); H, (6.02%); N, (16.17%).

INFO ABOUT INTERMEDIATE

5-(5-chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one

http://www.chemicalbook.com/ChemicalProductProperty_EN_CB11175931.htm

…………..

SYNTHESIS OF

http://www.google.co.in/patents/US6362178

EXAMPLE 1A 2-Butyrylaminopropionic acid 

 

22.27 g (250 mmol) of D,L-alanine and 55.66 g (550 mmol) of triethylamine are dissolved in 250 ml of dichloromethane, and the solution is cooled to 0° C. 59.75 g (550 mmol) of trimethylsilyl chloride are added dropwise, and the solution is stirred for 1 hour at room temperature and for 1 hour at 40° C. After cooling to −10° C., 26.64 g (250 mmol) of butyryl chloride are added dropwise, and the resulting mixture is stirred for 2 hours at −10° C. and for one hour at room temperature.

With ice-cooling, 125 ml of water are added dropwise and the reaction mixture is stirred at room temperature for 15 minutes. The aqueous phase is evaporated to dryness, the residue is titrated with acetone and the mother liquor is filtered off with suction. The solvent is removed and the residue is chromatographed. The resulting product is dissolved in 3N aqueous sodium hydroxide solution and the resulting solution is evaporated to dryness. The residue is taken up in conc. HCl and once more evaporated to dryness. The residue is stirred with acetone, precipitated solid is filtered off with suction and the solvent is removed under reduced pressure. This gives 28.2 g (71%) of a viscous oil which crystallizes after some time.

200 MHz ¹H-NMR (DMSO-d6): 0.84, t, 3H; 1.22, d, 3H; 1.50, hex, 2H; 2.07, t, 2H; 4.20, quin., 1H; 8.09, d, 1H.

EXAMPLE 3A 2-Ethoxybenzonitrile 

 

25 g (210 mmol) of 2-hydroxybenzonitrile are refluxed with 87 g of potassium carbonate and 34.3 g (314.8 mmol) of ethyl bromide in 500 ml of acetone overnight. The solid is filtered off, the solvent is removed under reduced pressure and the residue is distilled under reduced pressure. This gives 30.0 g (97%) of a colourless liquid.

200 MHz ¹H-NMR (DMSO-d6): 1.48, t, 3H; 4.15, quart., 2H; 6.99, dt, 2H; 7.51, dt, 2H.

EXAMPLE 4A 2-Ethoxybenzamidine hydrochloride 

 

21.4 g (400 mmol) of ammonium chloride are suspended in 375 ml of toluene, and the suspension is cooled to 0° C. 200 ml of a 2M solution of trimethylaluminium in hexane are added dropwise, and the mixture is stirred at room temperature until the evolution of gas has ceased. After addition of 29.44 g (200 mmol) of 2-ethoxybenzonitrile, the reaction mixture is stirred at 80° C. (bath) overnight.

With ice-cooling, the cooled reaction mixture is added to a suspension of 100 g of silica gel and 950 ml of chloroform, and the mixture is stirred at room temperature for 30 minutes. The mixture is filtered off with suction, and the filter residue is washed with the same amount of methanol. The mother liquor is concentrated, the resulting residue is stirred with a mixture of dichloromethane and methanol (9:1), the solid is filtered off with suction and the mother liquor is concentrated. This gives 30.4 g (76%) of a colourless solid.

200 MHz ¹H-NMR (DMSO-d6): 1.36, t, 3H; 4.12, quart., 2H; 7.10, t, 1H; 7.21, d, 1H; 7.52, m, 2H; 9.30, s, broad, 4H.

EXAMPLE 10A 2-(2-Ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

7.16 g (45 mmol) of 2-butyrylamino-propionic acid and 10.67 g of pyridine are dissolved in 45 ml of THF and, after addition of a spatula tip of DMAP, heated to reflux. 12.29 g (90 mmol) of ethyl oxalyl chloride are slowly added dropwise, and the reaction mixture is refluxed for 3 hours. The mixture is poured into ice-water and extracted three times with ethyl acetate and the organic phase is dried over sodium sulphate and concentrated using a rotary evaporator. The residue is taken up in 15 ml of ethanol and refluxed with 2.15 g of sodium bicarbonate for 2.5 hours. The cooled solution is filtered.

With ice-cooling, 2.25 g (45 mmol) of hydrazine hydrate are added dropwise to a solution of 9.03 g (45 mmol) of 2-ethoxybenzamidine hydrochloride in 45 ml of ethanol, and the resulting suspension is stirred at room temperature for another 10 minutes. The ethanolic solution described above is added to this reaction mixture, and the mixture is stirred at a bath temperature of 70° C. for 4 hours. After filtration, the mixture is concentrated, the residue is partitioned between dichloromethane and water, the organic phase is dried over sodium sulphate and the solvent is removed under reduced pressure.

This residue is dissolved in 60 ml of 1,2-dichloroethane and, after addition of 7.5 ml of phosphorus oxychloride, refluxed for 2 hours. The mixture is diluted with dichloromethane and neutralized by addition of sodium bicarbonate solution and solid sodium bicarbonate. The organic phase is dried and the solvent is removed under reduced pressure. Chromatography using ethyl acetate and crystallization afford 4.00 g (28%) of a colourless solid, R_f=0.42 (dichloromethane/methanol=95:5)

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.56, t, 3H; 1.89, hex, 2H; 2.67, s, 3H; 3.00, t, 2H; 4.26, quart., 2H; 7.05, m, 2H; 7.50, dt, 1H; 8.17, dd, 1H; 10.00, s, 1H.

EXAMPLE 15A 4-Ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride

At 0° C., 2.00 g (6.4 mmol) of 2-(2-ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one are slowly added to 3.83 ml of chlorosulphonic acid. At room temperature, the reaction mixture is stirred ovemight, and then poured into ice-water and extracted with dichloromethane. This gives 2.40 g (91%) of a colourless foam.

200 MHz ¹H-NMR (CDCl₃): 1.03, t, 3H; 1.61, t, 2H; 1.92, hex, 2H; 2.67, s, 3H; 3.10, t, 2H; 4.42, quart., 2H; 7.27, t, 1H; 8.20, dd, 1H; 8.67, d, 1H; 10.18, s, 1H.

Example 22 2-[2-Ethoxy-5-(4-hydroxyethyl-1-amino-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

By the same method, starting with 0.04 g (0.097 mmol) of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride and 0.04 g (0.29 mmol) of 1-amino-4-hydroxyethylpiperazine, 46 mg (91%) of 2-[2-ethoxy-5-(4-hydroxyethyl-1-amino-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one are obtained.

R_f=0.08 (dichloromethane/methanol=19:1)

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.59, t, 3H; 1.90, sex., 2H; 2.49, m, 6H; 2.62, s, 3H; 2.71, m, 4H; 3.00, t, 2H; 3.55, t, 2H; 4.31, quart., 2H; 7.14, d, 1H; 8.05, dd, 1H; 8.60, d, 1H.

…………..

Methods of analysis

The development of lodenafil carbonate was reported by Toque et al. (2008). They observed the effects of lodenafil carbonate on rabbit and human corpus cavernosum relaxation, activity of PDE5 in human platelets, stability and metabolic studies in comparison with sildenafil and lodenafil, as well as the pharmacological evaluation of lodenafil carbonate after intravenous and oral administration in male beagles.

The determination of PDE activity, stability of lodenafil carbonate in human, dog and rat plasma and the pharmacokinetic parameters after a single intravenous or oral dose was carried out by LC-MS/MS analysis

Codevilla et al. (2011a) developed a stability-indicating reversed-phase liquid chromatography method using ultraviolet (UV) detection for the quantitative determination of lodenafil carbonate in tablets. The method can be useful for routine quality control assay and stability studies.

Another study for the determination of lodenafil carbonate in tablets was developed by Codevilla et al. (2011b). As an alternative to the LC method the authors suggested a UV-spectrophotometric method for the analysis of lodenafil carbonate in pharmaceutical form. The UV method offers advantages over other analytical methods due to its rapidity, simplicity, and lower cost. Recently, Codevilla et al. (2012) developed and validated a capillary zone electrophoresis (CZE) method for determination of lodenafil carbonate in drug products. There are some advantages to use the CZE method, such as rapid analysis, small sample and reagent consumption, high separation efficiency (Furlanetto et al., 2001; Yang et al., 2010). The results obtained from the UV-spectrophotometric method and CZE method were compared statistically with the LC method (Codevilla et al., 2011a) and the results showed no significant difference between these methods.

References

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VARDENAFIL

224785-90-4  ^{CAS NO}

Vardenafil hydrochloride (CAS NO.224785-91-5)

4-[2-Ethoxy-5-(4-ethylpiperazin-1-yl)sulfonyl-phenyl]-9-methyl-7-propyl-3,5,6,8-tetrazabicyclo[4.3.0]nona-3,7,9-trien-2-one

Vivanza, Vardenafil (INN), Levitra (TN),  STK642629, , LEVITRA

Vardenafil (INN) is a PDE5 inhibitor used for treating erectile dysfunction that is sold under the trade names Levitra (Bayer AG, GSK, and SP) andStaxyn.

Vardenafil was co-marketed by Bayer Pharmaceuticals, GlaxoSmithKline, and Schering-Plough under the trade name Levitra. As of 2005, the co-promotion rights of GSK on Levitra have been returned to Bayer in many markets outside the U.S. In Italy, Bayer sells vardenafil as Levitra and GSK sells it as Vivanza. Thus, because of European Union trade rules, parallel imports might result in Vivanza sold next to Levitra in the EU.

Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.

An orally disintegrating form, marketed as Staxyn, has been gaining approvals in countries such as the United States^[1] and Canada.^[2]

Vardenafil’s indications and contra-indications are the same as with other PDE5 inhibitors; it is closely related in function to sildenafil citrate (Viagra) and tadalafil (Cialis). The difference between the vardenafil molecule and sildenafil citrate is a nitrogen atom’s position and the change of sildenafil’spiperazine ring methyl group to an ethyl group. Tadalafil is structurally different from both sildenafil and vardenafil. Vardenafil’s relatively short effective time is comparable to but somewhat longer than sildenafil’s.

Beyond its indications for erectile dysfunction, vardenafil may be effective in the treatment of premature ejaculation, where it may significantly increase the time from vaginal penetration to ejaculation.^[3]

The common, adverse drug reactions (side-effects) are the same as with other PDE5 inhibitors. The frequent vardenafil-specific side-effect is nausea; the infrequent side-effects are abdominal pain, back pain, photosensitivity, abnormal vision, eye pain, facial edema, hypotension, palpitation,tachycardia, arthralgia, myalgia, rash, itch, and priapism.

One possibly serious, but rare, side-effect with vardenafil is heart attack. Also, in rare cases, vardenafil use may cause priapism, a very painful emergency condition that can cause impotence if left untreated.^[4]

On 18 October 2007, the U.S. Food and Drug Administration (FDA) announced that a warning about possible deafness (sudden hearing loss) would be added to the drug labels of Vardenafil, and other PDE5 inhibitors.^[5]

Vardenafil, as with all PDE5 inhibitors, should not be used by men taking nitrate medications, because combining them with vardenafil might provoke potentially life-threatening hypotension (low blood pressure).

Further, Vardenafil causing lengthening of the QT interval. Therefore it should not be taken by men taking other medications that affect the QT interval (such as amiodarone).

Levitra 20mg Oral Tablet

It is available in 2.5 mg, 5 mg, 10 mg, and 20 mg doses in round orange tablets. The normal starting dose is 10 mg (roughly equivalent to 50 mg of sildenafil). Vardenafil should be taken 1 to 2 hours prior to sexual activity, with a maximum dose frequency of once per day. In some territories, such as the UK, only certain doses may be available.

Vardenafil is also available under the name Staxyn as a tablet which dissolves on the tongue rather than being swallowed in the form of a pill.

STAXYN is an oral therapy for the treatment of erectile dysfunction. This monohydrochloride salt of vardenafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific PDE5.

Vardenafil HCl is designated chemically as piperazine, 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-4-ethyl-, monohydrochloride and has the following structural formula:

Vardenafil HCl is a nearly colorless, solid substance with a molecular weight of 579.1 g/mol and a solubility of 0.11 mg/mL in water.

LEVITRA

TRIHYDRATE, HCL SALT

vardenafil hydrochloride is piperazine, 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1-f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-4-ethyl-, mono -hydrochloride and can be structurally represented by Formula I.

The monohydrochloride salt of vardenafil is a selective inhibitor of cyclic guaosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). It is commercially available in products sold under the brand name LEVITRA formulated as 2.5 mg, 5 mg, 10 mg, 20 mg film-coated tablets.

U.S. Pat. No. 6,362,178 B1 discloses vardenafil, its related compounds and processes for their preparation. The patent describes a process in which vardenafil is obtained by recrystallization in ether in Example 19. Vardenafil produced as per Example 19 is hereinafter referred as “crystalline Form I” of vardenafil. The patent also describes processes for the preparation of its monohydrochloride and dihydrochloride salts, which are formed in a combination of ether and dichloromethane. The patent also describes a process for the preparation of vardenafil monohydrochloride trihydrate.

U.S. Patent Application Publication No. 2005/0203298 also describes a process for the preparation of vardenafil, and its monohydrochloride trihydrate.

Chemical synthesis of vardenafil has mostly been directed to the preparation of the trihydrate of monohydrochloride of vardenafil.

In WO 99/24433, sulphonamide-substituted imidazotriazinones are described as potent inhibitors of either one or more of the cyclic guanosine 3′,5′-monophosphate-metabolizing phosphodiesterases (cGMP PDEs). According to the nomenclature of Beavo and Reifsnyder (Trends in Pharmacol. Sci. 11, 150-155, 1990), these cGMP PDEs are the phosphodiesterase isoenzymes PDE-I, PDE-II and PDE-V.

According to WO 99/24433, the sulphonamide-substituted imidazotriazinones described therein are prepared from corresponding 2-ethoxyphenyl-substituted imidazotriazinones by reaction with chlorosulphonic acid and subsequent reaction with an appropriate amine, as is illustrated by the following scheme (R¹ to R⁶ here have the meanings indicated in WO 99/24433):

In this process, highly reactive chlorosulphonic acid has to be used as a reagent. Moreover, the imidazotriazinonesulphonyl chlorides formed as intermediates are sensitive to hydrolysis, which, in particular in the conversion of this preparation process to the industrial scale, can lead to not inconsiderable yield variations.

It was therefore the object of the present invention to make available a process for the preparation of sulphonamide-substituted imidazotriazinones in which the disadvantages of the above process known from the prior art are avoided.

This object is achieved according to the present invention by a process as in claim 1. In particular, in the process according to the invention as in claim 1 the use of chlorosulphonic acid is avoided by introduction of the sulphonic acid via a reaction with sulphuric acid and subsequent reaction with thionyl chloride. Moreover, the reaction with thionyl chloride and the subsequent reaction with an amine is carried out in a one-pot process, so that the imidazotriazinonesulphonyl chloride intermediate, which is sensitive to hydrolysis, does not need to be isolated. By means of this, yield variations on account of partial hydrolysis of this intermediate can be excluded. As a result of these advantages, the process according to the invention is much simpler to carry out on the industrial scale than the process described in WO 99/24433.

………………….

SYNTHESIS

US6362178

2-butyrylamino-propionic acid

EXAMPLE 1A 2-Butyrylaminopropionic acid

 

22.27 g (250 mmol) of D,L-alanine and 55.66 g (550 mmol) of triethylamine are dissolved in 250 ml of dichloromethane, and the solution is cooled to 0° C. 59.75 g (550 mmol) of trimethylsilyl chloride are added dropwise, and the solution is stirred for 1 hour at room temperature and for 1 hour at 40° C. After cooling to −10° C., 26.64 g (250 mmol) of butyryl chloride are added dropwise, and the resulting mixture is stirred for 2 hours at −10° C. and for one hour at room temperature.

With ice-cooling, 125 ml of water are added dropwise and the reaction mixture is stirred at room temperature for 15 minutes. The aqueous phase is evaporated to dryness, the residue is titrated with acetone and the mother liquor is filtered off with suction. The solvent is removed and the residue is chromatographed. The resulting product is dissolved in 3N aqueous sodium hydroxide solution and the resulting solution is evaporated to dryness. The residue is taken up in conc. HCl and once more evaporated to dryness. The residue is stirred with acetone, precipitated solid is filtered off with suction and the solvent is removed under reduced pressure. This gives 28.2 g (71%) of a viscous oil which crystallizes after some time.

200 MHz ¹H-NMR (DMSO-d6): 0.84, t, 3H; 1.22, d, 3H; 1.50, hex, 2H; 2.07, t, 2H; 4.20, quin., 1H; 8.09, d, 1H.

EXAMPLE 3A 2-Ethoxybenzonitrile

 

25 g (210 mmol) of 2-hydroxybenzonitrile are refluxed with 87 g of potassium carbonate and 34.3 g (314.8 mmol) of ethyl bromide in 500 ml of acetone overnight. The solid is filtered off, the solvent is removed under reduced pressure and the residue is distilled under reduced pressure. This gives 30.0 g (97%) of a colourless liquid.

200 MHz ¹H-NMR (DMSO-d6): 1.48, t, 3H; 4.15, quart., 2H; 6.99, dt, 2H; 7.51, dt, 2H.

EXAMPLE 4A 2-Ethoxybenzamidine hydrochloride

 

21.4 g (400 mmol) of ammonium chloride are suspended in 375 ml of toluene, and the suspension is cooled to 0° C. 200 ml of a 2M solution of trimethylaluminium in hexane are added dropwise, and the mixture is stirred at room temperature until the evolution of gas has ceased. After addition of 29.44 g (200 mmol) of 2-ethoxybenzonitrile, the reaction mixture is stirred at 80° C. (bath) overnight.

With ice-cooling, the cooled reaction mixture is added to a suspension of 100 g of silica gel and 950 ml of chloroform, and the mixture is stirred at room temperature for 30 minutes. The mixture is filtered off with suction, and the filter residue is washed with the same amount of methanol. The mother liquor is concentrated, the resulting residue is stirred with a mixture of dichloromethane and methanol (9:1), the solid is filtered off with suction and the mother liquor is concentrated. This gives 30.4 g (76%) of a colourless solid.

200 MHz ¹H-NMR (DMSO-d6): 1.36, t, 3H; 4.12, quart., 2H; 7.10, t, 1H; 7.21, d, 1H; 7.52, m, 2H; 9.30, s, broad, 4H.

EXAMPLE 10A 2-(2-Ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

 

7.16 g (45 mmol) of 2-butyrylamino-propionic acid and 10.67 g of pyridine are dissolved in 45 ml of THF and, after addition of a spatula tip of DMAP, heated to reflux. 12.29 g (90 mmol) of ethyl oxalyl chloride are slowly added dropwise, and the reaction mixture is refluxed for 3 hours. The mixture is poured into ice-water and extracted three times with ethyl acetate and the organic phase is dried over sodium sulphate and concentrated using a rotary evaporator. The residue is taken up in 15 ml of ethanol and refluxed with 2.15 g of sodium bicarbonate for 2.5 hours. The cooled solution is filtered.

With ice-cooling, 2.25 g (45 mmol) of hydrazine hydrate are added dropwise to a solution of 9.03 g (45 mmol) of 2-ethoxybenzamidine hydrochloride in 45 ml of ethanol, and the resulting suspension is stirred at room temperature for another 10 minutes. The ethanolic solution described above is added to this reaction mixture, and the mixture is stirred at a bath temperature of 70° C. for 4 hours. After filtration, the mixture is concentrated, the residue is partitioned between dichloromethane and water, the organic phase is dried over sodium sulphate and the solvent is removed under reduced pressure.

This residue is dissolved in 60 ml of 1,2-dichloroethane and, after addition of 7.5 ml of phosphorus oxychloride, refluxed for 2 hours. The mixture is diluted with dichloromethane and neutralized by addition of sodium bicarbonate solution and solid sodium bicarbonate. The organic phase is dried and the solvent is removed under reduced pressure. Chromatography using ethyl acetate and crystallization afford 4.00 g (28%) of a colourless solid, R_f=0.42 (dichloromethane/methanol=95:5)

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.56, t, 3H; 1.89, hex, 2H; 2.67, s, 3H; 3.00, t, 2H; 4.26, quart., 2H; 7.05, m, 2H; 7.50, dt, 1H; 8.17, dd, 1H; 10.00, s, 1H.

EXAMPLE 15A 4-Ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride

 

 

At 0° C., 2.00 g (6.4 mmol) of 2-(2-ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one are slowly added to 3.83 ml of chlorosulphonic acid. At room temperature, the reaction mixture is stirred ovemight, and then poured into ice-water and extracted with dichloromethane. This gives 2.40 g (91%) of a colourless foam.

200 MHz ¹H-NMR (CDCl₃): 1.03, t, 3H; 1.61, t, 2H; 1.92, hex, 2H; 2.67, s, 3H; 3.10, t, 2H; 4.42, quart., 2H; 7.27, t, 1H; 8.20, dd, 1H; 8.67, d, 1H; 10.18, s, 1H.

Example 19 2-[2-Ethoxy-5-(4-ethyl-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

 

 

470 mg (1.14 mmol) of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride are dissolved in 20 ml of dichloromethane and cooled to 0° C. 390 mg (3.42 mmol) of N-ethylpiperazine are added, and the reaction mixture is stirred at room temperature overnight. The mixture is diluted with dichloromethane, the organic phase is washed twice with water and dried over sodium sulphate and the solvent is removed under reduced pressure. Crystallization from ether gives 370 mg (66%) of a colourless solid.

400 MHz ¹H-NMR (CDCl₃): 1.01, t, 3H; 1.59, t, 3H; 1.88, hex, 2H; 2.42, quart., 2H; 2.56, m, 4H; 2.63, s, 3H; 3.00, t, 2H; 3.10, m, 4H; 4.33, quart., 2H, 7.17, d, 1H; 7.88, dd, 1H; 8.44, d, 1H; 9.75, s, 1H.

…………………….

US7977478

EXAMPLE 7 Preparation of the Trihydrate of Vardenafil Monohydrochloride

14 g of vardenafil hydrochloride was taken into a round bottom flask followed by the addition of 70 ml water and the pH of the reaction mass was adjusted using sodium hydroxide to 11 at 30° C. 280 ml of dichloromethane was added to the above reaction mass and the layers were separated. The organic layer was dried over sodium sulfate and the organic layer was transferred into a round bottom flask and subjected to heating for distillation at 40° C. for 1.5 hours. The solid material was transferred into a round bottom flask and 36 ml of a mixture of acetone and water in 12:1 ratio was added with stirring, then 2.2 ml of 36% aqueous hydrochloric acid was added with stirring. The reaction mass was heated to a temperature of about 45° C. and the undissolved particles were removed by filtration. The filtrate was taken into a round bottom flask and cooled to 5° C., maintained for 45 minutes at 3 to 5° C. followed by the filtration of the solid which was then subjected to suction drying and finally dried at 40° C. to yield 9.0 g of the trihydrate of vardenafil monohydrochloride.

……………………..

US20050203298

STARTING COMPOUNDS

Example I Preparation of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo-[5,1-f][2,4]triazin-4-oneIa) Preparation of 2-butyrylaminopropionic acid

A solution of 100 kg of D,L-alanine in aqueous sodium hydroxide solution is reacted in the cold with 119 kg of butyryl chloride. After addition of butyl acetate, the mixture is acidified with hydrochloric acid, the organic phase is separated off and the aqueous phase is re-extracted. The organic phase is dried by azeotropic distillation. The crystallizate is isolated, washed with butyl acetate and dried.

Yield: 132.6 kg (68%)

¹H-NMR: δ=0.8 (t, 3H), 1.25 (d, 3H), 1.5 (m, 2H), 2.1 (t, 2H), 4.2 (q, 1H), 8.1 (d, NH), 12.0-12.7 (s, COOH)

MS: 336 (2M+NH₄, 40), 319 (2M+H, 15), 177 (M+NH₄, 100), 160 (M+H, 20)

Ib) Preparation of 2-ethoxybenzonitrile

260 kg of thionyl chloride are added at 85-95° C. to a suspension of 250 kg of 2-ethoxybenzamide in toluene under metering control. The reaction mixture is stirred in the presence of heat. Thionyl chloride and toluene are then distilled off in vacuo. The product is employed in the subsequent stage as a crude product.

Yield: 228.5 kg (crude product)

¹H-NMR: δ=1.45 (t, 3H), 4.15 (q, 2H), 7.0 (m, 2H, phenyl), 7.5 (m, 2H, phenyl)

MS: 312 (2M+N₄, 35), 165 (M+NH₄, 100), 147 (5)

Ic) Preparation of 2-ethoxy-N-hydroxybenzamidine

111 kg of 2-ethoxybenzonitrile (crude product) from Example Ib are heated under reflux with 164 1 of triethylamine and 73 kg of hydroxylamine hydrochloride in isopropanol. The reaction mixture is treated with water and cooled. The crystallizate is isolated, washed and employed in the subsequent stage as a moist product.

Yield: 92.6 kg (moist product)

¹H-NMR: δ=1.35 (t, 3H), 4.1 (q, 2H), 5.6 (s, 2H), 6.9-7.4 (4H, phenyl), 9.4 (s, 1H, OH)

MS: 361 (2M+H, 30), 198 (M+N, 30), 181 (M+H, 100)

Id) Preparation of 2-ethoxybenzamidine hydrochloride

135 kg of 2-ethoxy-N-hydroxybenzamidine (moist product) from Example Ic are hydrogenated at 50-60° C. in acetic acid using palladium on carbon as a catalyst. For the work-up, the hydrogenation reaction is freed from the catalyst, treated with hydrochloric acid and concentrated. Residual acetic acid and water are removed by azeotropic distillation with toluene. The crystallizate is isolated and dried in vacuo.

Yield: 136.4 kg

H-NMR: 1.35 (t, 3H), 4.15 (q, 2H), 7.1-7.7 (m, 4H, phenyl), 9.1-9.4 (2×s, 3H), 10.5-10.7 (s, 1H)

MS: 329 (2M+H, 10), 165 (M+H, 100)

Ie) Preparation of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]-triazin-4-one

231 kg of 2-butyrylaminopropionic acid from Example Ia are treated in tetrahydrofuran with 341 kg of pyridine, catalytic amounts of 4-N,N-dimethylaminopyridine and 392 kg of ethyl chloroxalate and stirred with heating under reflux. The reaction mixture is taken up in ethyl acetate, washed with water and the ethyl acetate phase is concentrated. The distillation residue is taken up in methanol and reacted with the following solution.

192 kg of 2-ethoxybenzamidine hydrochloride from Example Id are treated in methanol with 47.5 kg of hydrazine hydrate and the mixture is stirred at room temperature. The solution is combined with the solution of 2-butyrylamino-1-ethoxycarbonylpropenyl ethyl oxalate prepared above. The reaction mixture thus obtained is stirred with heating under reflux. Methanol is removed by distillation and replaced by acetic acid.

Option A:

138.6 kg of phosphorus oxychloride are added and stirred in the presence of heat.

Acetic acid is distilled off in vacuo. The residue is treated with water and dichloromethane or optionally methyl isobutyl ketone and rendered neutral using sodium hydroxide solution. The organic phase is concentrated, and the residue is dissolved in acetone and crystallized with cooling. The crystallizate is isolated, washed and dried.

Option B:

At least 190 kg of acetyl chloride are added and stirred in the presence of heat. Acetic acid is distilled off in vacuo. The distillation residue is treated with acetone and water, and the product is crystallized by rendering neutral with sodium hydroxide solution. The product is isolated, washed and dried.

Yield: 90-160 kg

¹H-NMR: δ=1.0 (t, 3H), 1.6 (t, 3H), 1.9 (m, 2H), 2.8 (s, 3H), 3.3 (t, 2H), 4.3 (q, 2H), 7.0-8.2 (Ar, 4H), 10.3 (CONH, 1H)

MS: 313 (M+H, 100), 149 (25), 151 (40), 121 (15)

HPLC: Kromasil C-18 phase, neutral phosphate buffer, acetonitrile, 233 nm, linear gradient of 30% acetonitrile ->80% acetonitrile (30 min.): 99 area % (R_t 19.1)

PREPARATION EXAMPLES Example 1a 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydroimidazo[5,1-fl-][1,2,4]triazin-2-yl)benzenesulphonic acid

194 kg of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one from Example Ie are reacted with 504 kg of concentrated sulphuric acid. The reaction mixture is added to water, cooled, and the crystallizate is isolated and dried in vacuo.

Yield: 195.2 kg

¹H-NMR: δ=0.95 (t, 3H), 1.3 (t, 3H), 1.8 (m, 2H), 2.6 (s, 3H), 3.05 (t, 2H), 4.1 (q, 2H), 7.15 (Ar, 1H), 7.75 (m, 2H), 12.3 (SO₂OH)

MS: 393 (M+H, 100), 365 (25), 151 (40)

HPLC: X-Terra C-18 phase, aqueous phosphoric acid, acetonitrile, 242 nm, linear gradient of 10% acetonitrile ->90% acetonitrile (20 min.):

98 area % (R, 9.2)

Example 1b) 2-[2-ethoxy-5-(4-ethlylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

22.5 kg of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]-triazin-2-yl)benzenesulphonic acid from Example 1a are reacted with 74 kg of thionyl chloride and catalytic amounts of dimethylformamide until the evolution of gas has ended. Xylene is repeatedly added to the reaction mixture and thionyl chloride is distilled off. 15.1 kg of N-ethylpiperazine are added to the suspension and it is stirred. After the addition of water, it is adjusted to pH 1 using hydrochloric acid, and the phases are separated. The aqueous phase is treated with acetone and rendered neutral by addition of sodium hydroxide solution. The mixture is cooled, and the crystallizate is isolated, washed and dried in vacuo.

Yield: 26.1 kg

¹H-NMR: δ=1.0 (2×t, 6H), 1.6 (t, 3H), 1.9 (m, 2H), 2.45 (q, 2H), 2.55 (m, 4H), 2.65 (s, 3H), 3.0 (t, 2H), 3.1 (m, 4H), 4.35 (q, 2H), 7.15 (Ar, 1H), 7.9 (Ar, 1H), 8.4 (Ar, 1H), 9.8 (CONH)

MS: 489 (M+H, 100), 345 (10), 313, (10), 285 (10), 113 (20)

HPLC: X-Terra C-18 phase, neutral phosphate buffer, acetonitrile, 242 nm, linear gradient of 20% acetonitrile ->75% acetonitrile (20 min.): 98 area % (R_t 16.3)

1 c) 2-[2-ethoxy-5-(4-ethylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-fl][1,2,4]triazin-4-one hydrochloride trihydrate

22.5 kg of 2-[2-ethoxy-5-(4-ethylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one from Example 1b are dissolved in 5.1 kg of concentrated hydrochloric acid and acetone/water (12:1 v/v) in the presence of heat. The clear solution is filtered hot and crystallized by cooling and seeding. The crystallizate is isolated, washed and dried in vacuo at about 30° C. and about 300 mbar.

Yield: 25.4 kg

M.p. (DSC): 192° C.

HPLC: X-Terra C-18 phase, neutral phosphate buffer, acetonitrile, 242 nm, linear gradient of 20% acetonitrile ->75% acetonitrile (20 min.): 99 area % (R_t 16.3)

• Official Levitra website
• PubChem Information

• 23313637

  2-1-2013

  Synthesis of quinoline derivatives: discovery of a potent and selective phosphodiesterase 5 inhibitor for the treatment of Alzheimer’s disease.

  European journal of medicinal chemistry

PATENTS

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Tadataka Yamada, M.D., Chief Medical & Scientific Officer of Takeda

TAKEDA US CHICAGO OFFICE

TAKEDA PIPELINE SEE LINKS BELOW

1    https://www.takeda.com/investor-information/annual/files/ar2013_10_en.pdf

2. http://www.takeda.com/research/files/pipeline_20131031_en.pdf

3  http://www.takeda.com/research/pipeline/

• 2012 Download Entire File  PDF 0.4MB 34P

R&D Pipeline (As of October 31, 2013)

PDF 1.0MB 18P

Takeda’s top executives had frequently pointed to TAK-875 as one of their best shots at coming up with an important new approach to treating diabetes. The drug is designed to spur insulin secretion in the pancreas and Takeda had confidently projected an approval in Japan in 2015 with a follow-up approval in the big U.S. market a year or two later.

The termination of the high-profile program caused some anxiety among investors. Takeda’s shares plunged 8% on the loss as analysts wondered how the pharma company could counter the loss of Actos, a $3.7 billion drug that accounted for about a quarter of its revenue in 2011.

Takeda won an approval on a trio of DPP-4 diabetes drugs–Nesina (alogliptin) and two combos with alogliptin, dubbed Oseni and Kazano–at the beginning of the year. But Takeda suffered some big delays in gaining acceptance, a common fate in this field, where regulators are particularly cautious about new drugs. And Merck  had already solidified its lead in the DPP-4 market with Januvia whileOnglyza trailed closely behind it. Takeda had hoped that a combination of TAK-875 and Januvia could help regain some lost market territory–but that dream has clearly vanished as well.

2013

CLIPPED

Takeda isn’t quite in the top 10 among global drugmakers, but the company boasts the 7^th-largest pipeline in the industry, according to its presentation at the conference. Yamada noted that 31% of the pipeline assets are in late-stage trials. Millennium is leading development of three late-stage contenders, TAK-700 for prostate cancer, MLN9708 for multiple myeloma and MLN0002 for ulcerative colitis andCrohn’s disease.

In an effort to revive its diabetes franchise, Takeda is in the final stage of development for a first-of-a-kind GPR40 agonist called TAK-875, designed to provide glucose-dependent insulin secretion.

With a rich late-stage pipeline at Takeda, Yamada wants the company to focus on growing its ranks of earlier-stage drug candidates. To do this the company has landed a variety of deals, including the purchase of Intellikine for $310 million to acquire anti-cancer drugs and more recently the acquisition of Envoy Therapeutics last year for $140 million.

Takeda has formed a New Frontier Science group to scout out the hottest research in academia and elsewhere and form collaborations with scientists behind those innovations. At the J.P. Morgan conference, Yamada said, he was attending many meetings with members of the biotech community.

Takeda Pharmaceutical Company Limited (武田薬品工業株式会社 Takeda Yakuhin Kōgyō Kabushiki-gaisha^?) is the largest pharmaceutical company in Japan and Asia and a top 15 pharmaceutical company. The company has over 30,000 employees worldwide and achieved $16.2 billion USD in revenue during the 2012 fiscal year.^[1] The company is focused on metabolic disorders, gastroenterology, neurology, inflammation, as well asoncology through its independent subsidiary, Millennium: The Takeda Oncology Company.^[2] Its headquarters is located in Chuo-ku, Osaka, and it has an office in Nihonbashi, Chuo, Tokyo.^[3][4] In January 2012, Fortune Magazine ranked the Takeda Oncology Company as one the 100 best companies to work for in the United States.

Takeda Pharmaceuticals was founded on June 12, 1781 and was incorporated on January 29, 1925.

Takeda’s Japanese logo

In 1977, Takeda first entered the U.S. pharmaceutical market by developing a joint venture with Abbott Laboratories called TAP Pharmaceuticals.^[5]Through TAP Pharmaceuticals, Takeda and Abbott launched the blockbusters Lupron (leuprolide) in 1985 and Prevacid (lansoprazole) in 1995.

One of the firm’s mainstay drugs is Actos, a compound in the thiazolidinedione class of drugs used in the treatment of type 2 diabetes. Launched in 1999, Actos has become the best-selling diabetes drug in the world with $4 billion USD in sales during the 2008 fiscal year.^[6]

In February 2005, Takeda announced its acquisition of San Diego, California-based Syrrx, a company specializing in high-throughput X-ray crystallography, for $270 million.^[7]

In February 2008, Takeda acquired the Japanese operations of Amgen and rights to a dozen of the California biotechnology company’s pipeline candidates for the Japanese market.^[8]

In March 2008, Takeda and Abbott Laboratories announced plans to conclude their 30-year old joint venture, TAP Pharmaceuticals, that had over $3 billion in sales in its final year. The split resulted in Abbott acquiring U.S. rights to Lupron and the drug’s support staff. On the other hand, Takeda received rights to Prevacid and TAP’s pipeline candidates. The move also increased Takeda’s headcount by 3,000 employees.^[9]

In April 2008, Takeda announced that it was acquiring Millennium Pharmaceuticals of Cambridge, Massachusetts, a company specializing in cancerdrug research, for $8.8 billion. The acquisition brought in Velcade, a drug indicated for hematological malignancies, as well as a portfolio of pipeline candidates in the oncology, inflammation, and cardiovascular therapeutic areas. Millennium now operates as an independent subsidiary, serving as the global center of excellence in oncology under its new name: “Millennium: The Takeda Oncology Company.” ^[10]

In May 2008, the company licensed non-exclusively the RNAi technology platform developed by Alnylam Pharmaceuticals, creating a potentially long-term partnership between the companies.^[11]

On May 19, 2011, Takeda Pharmaceutical and Nycomed announced that Takeda will acquire Nycomed for € 9.6 billion. The acquisition was completed by September 30, 2011.^[12]

On April 11, 2012, Takeda Pharmaceutical and URL Pharma announced that Takeda will acquire URL Pharma for $800 million. The acquisition is expected to be completed within 60 days.

On 25 May 2012, Takeda announced the purchase of Brazilian pharmaceutical company Multilab by R$ 540 million.^[13]

Takeda Midosuji Building, headquarters of Takeda Pharmaceutical Company, inChuo-ku, Osaka, Japan

Takeda operates two primary bases in Japan in Osaka and Tokyo. Its United States subsidiary is based in Deerfield, Illinois, and all Global Operations outside of Japan and U.S. are based in Opfikon (Zurich), Switzerland. The company maintains research & development sites in Osaka and Tsukuba, Japan; San Diego andSan Francisco, United States; Cambridge, United Kingdom; and Singapore.^[14]

The company has manufacturing facilities in Japan, China, Indonesia, Italy, and Ireland.^[15] Following the Nycomed acquisition, the Takeda manufacturing sites have been extended with facilities in Argentina,Austria,Belgium,Brazil,Denmark, Estonia,Germany,Mexico,Norway and Poland. Takeda has overseas marketing presences in the U.S., UK, France, Italy, Germany, Austria, Switzerland, Spain, China, Taiwan, Philippines, Thailand, Indonesia, and Singapore. It has recently^[when?] announced its first foray into Canada, Portugal, Spain, Mexico, and Ireland.^[15]

AT INDONESIA

Products

Some of the key products that Takeda produces on behalf of partners include:^[16]

• Actos (pioglitazone) - Type 2 Diabetes
• Amitiza (lubiprostone) – Chronic idiopathic constipation
• Basen (voglibose) – Type 2 Diabetes
• Benet (risedronic acid) - Osteoporosis (Japan)
• Blopress (candesartan) - Hypertension
• Enbrel (etanercept) – Inflammatory diseases (Japan)
• Dexilant (dexlansoprazole) - Gastroesophageal reflux disease - name changed to Dexilant in U.S.
• Lupron/Leuplin (leuprorelin) – GnRH agonist for prostate cancer and endometriosis
• Prevacid/Takepron (lansoprazole) – Gastroesophageal reflux disease
• Rozerem (ramelteon) - Insomnia
• Uloric (febuxostat) - Gout
• Velcade (bortezomib) - Multiple myeloma and mantle cell lymphoma (Millennium Pharmaceuticals)

AT UK

References

• Takeda Pharmaceutical Company
• Wall Street Journal article on Takeda

Takeda Pharmaceutical Company Limited

Native name	武田薬品工業株式会社
Type	Public KK
Traded as	TYO: 4502 OTC Pink: TKPYY
Industry	Pharmaceuticals
Founded	Doshomachi, Osaka, Japan (June 12, 1781)
Headquarters	1-1, Doshomachi Yonchome,Chuo-ku, Osaka, Japan
Key people	Yasuchika Hasegawa (President & CEO)
Revenue	¥1,557,267 million (FY2012)[* 1]
Operating income	¥122,505 million (FY 2012)[* 1]
Net income	¥131,244 million (FY 2012)[* 1]
Total assets	¥3,955,599 million (FY 2012)[* 1]
Total equity	¥2,223,359 million (FY 2012)[* 1]
Employees	30,481 (2012)
Website	takeda.com (Global website)
References: “Financial Results for Fiscal 2012″ (PDF). Takeda Pharmaceutical Company Limited. May 9, 2013. Retrieved June 13, 2013.

CMC CENTRE

The Chemistry, Manufacturing and Controls (CMC) Center is a global organization responsible for overall R&D activities ranging from chemical information on development candidates to the processes leading to “manufacturing” of pharmaceutical products.

The main sites are located in Osaka and consist of the following laboratories: the Chemical Development Laboratories in charge of R&D for developing the manufacturing methods of active pharmaceutical ingredients and the manufacturing of drug substances for clinical samples; the Pharmaceutical Technology R&D Laboratories in charge of R&D for dosage forms, manufacturing and packaging, as well as manufacturing of clinical samples; and the Analytical Development Laboratories in charge of R&D for the development of analytical methods and stability studies of clinical samples. In addition, Hikari Bio-Manufacturing Technology Laboratories is located in Hikari (Yamaguchi) and this is where antibody drug substances are manufactured.

As for overseas sites, the Cambridge Biologics CMC Group (Massachusetts) and the Chicago Pharmaceutical Science Group (Illinois) are located in the USA, while the CMC Center Europe is mainly located in Roskilde, Denmark. All research and development activities at Takeda are promoted with the cooperation of these sites.

List of Publications of Takeda Research Laboratories

2012 Download Entire File	PDF 0.4MB 34P
2011 Download Entire File	PDF 0.5MB 26P
2010 Download Entire File	PDF 0.5MB 16P
2009 Download Entire File	PDF 0.5MB 16P
2008 Download Entire File	PDF 0.1MB 17P
2007 Download Entire File	PDF 0.1MB 15P
2006 Download Entire File	PDF 0.1MB 17P

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A strategy for the risk assessment of potentially genotoxic impurities is described that utilizes Quality by Design in an effort to furnish greater process and analytical understanding, ultimately leading to a determination of impurity criticality. By identifying the risks and parameters that most influence those risks, an enhancement of both product and process control is attained that mitigates the potential impact of these impurities. This approach calls for the use of toxicological testing where necessary, chemical fate arguments when possible, multivariate analyses to develop design space, and use of spiking data to support specifications. Strong analytical support, especially with the development of low-level detection methods, is critical. We believe that this strategy not only aids in the development of a robust API process but also delivers on the identification and subsequent mitigation of risks to a class of impurities that are of high interest in the field.

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WO2008067465A1 OR US8084605  IS THE PATENT USED AND WITH FORM “A” AND AMORPHOUS FORM

Active pharmaceutical ingredients (APIs), frequently delivered to the patient in the solid-state as part of an approved dosage form, can exist in such diverse solid forms as polymorphs, pseudopolymorphs, salts, co-crystals and amorphous solids. Various solid forms often display different mechanical, thermal, physical and chemical properties that can remarkably influence the bioavailability, hygroscopicity, stability and other performance characteristics of the drug.

Hence, a thorough understanding of the relationship between the particular solid form of an active pharmaceutical ingredient (API) and its functional properties is important in selecting the most suitable form of the API for development into a drug product. In past decades, there have been significant efforts on the discovery, selection and control of the solid forms of APIs and bulk drugs.

If you’re involved in late drug discovery, API manufacture, drug product formulation, clinical material production, or manufacture of final dosage form, a basic understanding and awareness of solid form issues could save you a great deal of difficulty, time, and money during drug development.

 

What is polymorphism?

Polymorphs are crystalline materials that have the same chemical composition but different molecular packing. The concept is well demonstrated by the different crystalline forms of carbon. Diamond, graphite, and fullerenes are all made of pure carbon, but their physical and chemical properties vary drastically. Polymorphs are one type of solid form. Other solid form types include solvates, hydrates, and amorphous forms.

Solvates are crystalline materials made of the same chemical substance, but with molecules of solvent regularly incorporated into a unique molecular packing. When water is the solvent, these are called hydrates. An amorphous form of a substance has the same chemical composition, but lacks the long-range molecular order of a crystalline form of the same substance. Many organic and inorganic compounds, including APIs, can exist in multiple solid forms.

Some APIs may have only one or two known solid forms. Others may exist in twenty different forms, each having different physical and chemical properties.

Solid form screening, including salt, polymorph, cocrystal and amorphous solid dispersions, is vitial for successful pharmaceutical development. With an increase in the size and complexity of the molecules that enter into drug development, companies face a larger number of compounds that are either poorly soluble, difficult to crystallize or problematic with respect to desired physical chemical properties hindering successful drug development.

Crystallics has an extensive track record in executing solid state research studies and its research team has a broad expertise in identifying new crystal forms as well as in solving problems related to polymorphism and crystallization.

Investigational new drug, writing an application for clinical trial authorization, permission marketing …The control of polymorphism in drug candidates is now ubiquitous.

READ………….An Overview of Solid Form Screening During Drug Development, http://www.icdd.com/ppxrd/10/presentations/PPXRD-10_Ann_Newman.pdf

ANN NEWMAN

When addressing the subject of polymorphism, the first reference that comes to mind is that of the occurred during the manufacture of ritonavir incident. Abbott molecule inhibitor of HIV protease marketed as Norvir, is a cautionary example of the challenges of polymorphism.

Indeed, during the production of ritonavir in 1997, a new polymorph unmarked emerged. Its precipitation and unexpected outbreak led to the cessation of the production of Norvir and seriously compromise the process. The incident has deeply marked the pharmaceutical industry.

It is ironic that the process used to discover pharmaceutical drug targets is the same one that decreases the actual efficacy of those drugs once ingested. If you remember from basic chemistry, there are compounds that exist in highly ordered crystalline states and those that remain in amorphous form.

The discovery of drug targets has often been accomplished through X-ray crystallography, which requires a sample (for example, of a defective enzyme linked to cancer or high cholesterol) to be crystallized so that the diffraction patterns can be made sense of. Scientists may spend years trying to crystallize one molecule or compound so that they can identify regions that, for example, may be blocked by pharmaceuticals.

However, when it comes to the molecular arrangement of those pharmaceuticals, crystallization actually decreases their bioavailability and solubility. Thus, it may be better for these drugs to be in amorphous form. Pierric Marchand, general manager of the company Holodiag, dedicated to the study and characterization of solid state, summarizes that “ today, it is not reasonable to not worry about the problem of polymorphism ” .

“ In recent years, manufacturers have realized the essential side of expertise , “says Jean-Rémi David, commercial director Calytherm. The services company specializing in the field of physico-chemical analysis, based in Herault, has just relocated last year in supporting pharmaceutical development to meet demand. ” This is a concern for all deal with potential impacts on the effectiveness or the formulation , “says Stéphane Suchet, quality manager in the group of fine and specialty chemicals Axyntis.

Polymorphic forms are the amorphous and crystalline forms such as hydrate or solvate forms. When a molecule of interest exists in polymorphic forms, it is called polymorphism, according to the definition of the FDA (Food and Drug Administration).

Polymorphism is present at all stages of development of a drug from research to marketing. ” Keep in mind that organic molecule loves to polymorphism , “says Marchand Pierric. However, for a marketing authorization for example, must learn the criteria for the polymorphism of the molecule. ” In terms of the formulation, for example we can check whether the selected polymorphism is unchanged , “explains Pierric Marchand.

A significant influence on several levels  Because the consequences of polymorphism are multiple. ” They are at three levels: bioequivalence, manufacturability and stability ”lists Fabienne Lacoulonche, founder and scientific director of Calytherm.In terms of bioequivalence, different polymorphic forms may have different properties of solubility and dissolution rate … ” For poorly soluble active ingredients, you can have much more bioavailable than other crystalline forms , “Fabienne Lacoulonche information.

In terms of manufacturability, some parameters such as temperature, moisture can lead to changes in the crystalline form. ” The complexity is to anticipate changes polymorphism, both at laboratory scale, pilot and industrial , “adds the founder of Calytherm. Finally, polymorphism plays on stability. Active ingredient or finished product, are subjected to stability studies in this direction. ” When the molecule is identified, we try to highlight the existence of several forms of polymorphism, explains Stéphane Suchet (Axyntis) . 

When developing a new substance, the assessment is systematic . “ Isolation of crystals from a screening is carried out in different solvents by various analytical techniques. Ideally, it will be concluded the absence of polymorphism. ” But if different polymorphic forms are present, we rework the terms of our crystallization process to control the formation of the same polymorph reproducibly ideally form the thermodynamically more stable , “says Stéphane Suchet. X-ray diffraction and other thermal analysis ”

The ICH guidelines provide decision trees to guide the industry in controlling polymorphism says Fabienne Lacoulonche (Calytherm.) We use it for writing the CTD (Common Technical Document) .

“Polymorphism is a phenomenon” complex and difficult to control, because the crystallization is dependent on many parameters , she develops. must understand the maximum . “ For this, several analytical methods are available to industry. The main technique is the X-ray diffraction ” It is a robust, rapid, which allows to characterize the different polymorphs , “summarizes Pierric Marchand (Holodiag).Non-destructive, it can work both on small quantities on large samples. Temperature and atmosphere are controlled, and analytical capabilities are broad.

But if this technique indispensable allows for routine and development, it is not sufficient in itself. Just to add a battery of additional tests, thermal analysis. ” It takes coupling methods “ confirms Fabienne Lacoulonche (Calytherm). The X-ray diffraction is a method of choice, but sometimes it is not sufficient.

The coupling with a thermal analysis method (technical ATG, or DSC thermal analysis, differential scanning calorimetry or thermomicroscopique) allows to distinguish between two polymorphic whose RX diffractograms obtained are comparable.

TGA can be coupled with IR or mass spectrometry, DSC with RX. Raman spectroscopy is also part of complementary methods. ” The difficulty increases when we want to characterize the shape of the active ingredient in the finished product , says Fabienne Lacoulonche. example, by X-ray diffraction, the peaks related to the active ingredient in the diffractogram of the finished product may be masked by those excipients: it is then necessary to use other methods, such as Raman microscopy. ”In general, a single method of analysis is not sufficient to characterize the polymorphism of an active substance in the active substance or finished product: the complementarity of different methods that will conclude precisely on the polymorphism of a crystalline substance.

In addition, “ the diffractometer remains an expensive device, which requires installation in an air-conditioned and a cooling room , “says Marchand Pierric (Holodiag). To this is added the need to have expertise and qualified personnel to carry out the analyzes. ” We must master these techniques and the ability to interpret the results , “says Jean-Rémi David (Calytherm). However, polymorphism is a “problem well under control , “said Stéphane Suchet (Axyntis),” systematically evaluated although it is however not always immune to miss a polymorphic form, knowing that the screening performed in the development can never be completely comprehensive … ”

FDA

FDA may refuse to approve an ANDA referencing a listed drug if the application contains insufficient information to show that the drug substance is the “same” as that of the reference listed drug. A drug substance in a generic drug product is generally considered to be the same as the drug substance in the reference listed drug if it meets the same standards for identity.

In most cases, the standards for identity are described in the USPalthough FDA may prescribe additional standards when necessary. Because drug product performance depends on the product formulation, the drug substance in a proposed generic drug product need not have the same physical form (particle size, shape, or polymorph form) as the drug substance in the reference listed drug. An ANDA applicant is required to demonstrate that the proposed product meets the standards for identity, exhibits sufficient stability and is bioequivalent to the reference listed drug.

FDA PRESENTATION……polymorphs and co-crystals – ICDD      Regulatory Considerations on Pharmaceutical Solids: Polymorphs/Salts and Co-Crystals.. THIS IS A MUST READ ITEM

Over the years FDA has approved many generic drug products based upon a drug substance with different physical form from that of the drug substance in the respective reference listed drug (e.g., warfarin sodium, famotidine, and ranitidine). Also many ANDAs have been approved in which the drug substances differed from those in the corresponding reference listed drugs with respect to solvation or hydration state (e.g., terazosin hydrochloride, ampicillin, and cefadroxil). Several regulatory documents and literature reports (67-69) address issues relevant to the regulation of polymorphism.

The concepts and principles outlined in these are applicable for an ANDA. However, certain additional considerations may be applicable in case of ANDAs. Often at the time FDA receives an ANDA a monograph defining certain key attributes of the drug substance and drug product may be available in the Unites States Pharmacopoeia (USP). These public standards play a significant role in the ANDA regulatory review process and in case of polymorphism, when some differences are noted, lead to additional requirements and considerations.

This commentary is intended to provide a perspective on polymorphism in pharmaceutical solid in the context of ANDAs. It highlights major considerations for monitoring and controlling drug substance polymorphs and describes a framework for regulatory decisions regarding drug substance “sameness” considering the role and impact of polymorphism in pharmaceutical solids.

Since polymorphs exhibit certain differences in physical (e.g., powder flow and compactability, apparent solubility and dissolution rate) and solid state chemistry (reactivity) attributes that relate to stability and bioavailability it is essential that the product development and the FDA review process pay close attention to this issue.

This scrutiny is essential to ensure that polymorphic differences (when present) are addressed via design and control of formulation and process conditions to physical and chemical stability of the product over the intended shelf-life, and bioavailability/bioequivalence.

Most pharmaceuticals are distributed as solid doseages. In order to take action, they must dissolve in the gut and be absorbed into the blood stream. In many cases, the rate at which the drug dissolves can limit its effectiveness. Pharmaceutical compounds can be packed into more than one arrangement in the solid states known as polymorphs. Rapid and efficient methods of polymorph formation can be used to increase drug efficacy and shelf life.

Regulatory agencies worldwide require that, as part of any significant filing, a company has to demonstrate that it has made a reasonable effort to identify the polymorphs of their drug substance and has checked for polymorph interconversions. Due to the unpredictable behaviour of polymorphs and their respective differences in physicochemical properties, companies also have to demonstrate consistency in manufacturing between batches of the same product. Proper understanding of the polymorph landscape and nature of the polymorphs will contribute to manufacturing consistency.

POLYMORPHISM AND PATENTS http://www.collegio.unibo.it/uploads/ideas/joelbernstein.pdf  A MUST CLICK FOR PHARMA CHEMISTS

READ………..High-throughput crystallization: polymorphs, salts, co-crystalsand solvates of pharmaceutical solidshttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.5397&rep=rep1&type=pdf

Definitions

“Crystalline”, as the term is used herein, refers to a material, which may be hydrated and/or solvated, and has sufficient ordering of the chemical moiety to exhibit a discernable diffraction pattern by XRPD or other diffraction techniques. Often, a crystalline material that is obtained by direct crystallization of a compound dissolved in a solution or by interconversion of crystals obtained under different crystallization conditions, will have crystals that contain the solvent used in the crystallization, termed a crystalline solvate. Also, the specific solvent system and physical embodiment in which the crystallization is performed, collectively termed crystallization conditions, may result in the crystalline material having physical and chemical properties that are unique to the crystallization conditions, generally due to the orientation of the chemical moieties of the compound with respect to each other within the crystal and/or the predominance of a specific polymorphic form of the compound in the crystalline material.

Depending upon the polymorphic form(s) of the compound that are present in a composition, various amounts of the compound in an amorphous solid state may also be present, either as a side product of the initial crystallization, and/or a product of degradation of the crystals comprising the crystalline material. Thus, crystalline, as the term is used herein, contemplates that the composition may include amorphous content; the presence of the crystalline material among the amorphous material being detectably among other methods by the composition having a discernable diffraction pattern.

The amorphous content of a crystalline material may be increased by grinding or pulverizing the material, which is evidenced by broadening of diffraction and other spectral lines relative to the crystalline material prior to grinding. Sufficient grinding and/or pulverizing may broaden the lines relative to the crystalline material prior to grinding to the extent that the XRPD or other crystal specific spectrum may become undiscernable, making the material substantially amorphous or quasi-amorphous. Continued grinding would be expected to increase the amorphous content and further broaden the XRPD pattern with the limit of the XRPD pattern being so broadened that it can no longer be discerned above noise. When the XRPD pattern is broadened to the limit of being indiscernible, the material may be considered no longer a crystalline material, but instead be wholly amorphous. For material having increased amorphous content and wholly amorphous material, no peaks should be observed that would indicate grinding produces another form.

“Amorphous“, as the term is used herein, refers to a composition comprising a compound that contains too little crystalline content of the compound to yield a discernable pattern by XRPD or other diffraction techniques. Glassy materials are a type of amorphous material. Glassy materials do not have a true crystal lattice, and technically resembling very viscous non-crystalline liquids. Rather than being true solids, glasses may better be described as quasi-solid amorphous material. “Broad” or “broadened”, as the term is used herein to describe spectral lines, including XRPD, NMR and IR spectroscopy, and Raman spectroscopy lines, is a relative term that relates to the line width of a baseline spectrum. The baseline spectrum is often that of an unmanipulated crystalline form of a specific compound as obtained directly from a given set of physical and chemical conditions, including solvent composition and properties such as temperature and pressure.

For example, broadened can be used to describe the spectral lines of a XRPD spectrum of ground or pulverized material comprising a crystalline compound relative to the material prior to grinding. In materials where the constituent molecules, ions or atoms, as solvated or hydrated, are not tumbling rapidly, line broadening is indicative of increased randomness in the orientation of the chemical moieties of the compound, thus indicative of an increased amorphous content. When comparisons are made between crystalline materials obtained via different crystallization conditions, broader spectral lines indicate that the material producing the relatively broader spectral lines has a higher level of amorphous material.

“About” as the term is used herein, refers to an estimate that the actual value falls within ±5% of the value cited. “Forked” as the term is used herein to describe DSC endotherms and exotherms, refers to overlapping endotherms or exotherms having distinguishable peak positions

. 

Classes of multicomponent pharmaceutical materials. (a) Schematic of crystalline materials showing neutral and charged species. The red box indicates polymorphs are possible for all the multicomponent crystals contained within the box (adapted from Reference 7). (b) Schematic of amorphous solid dispersions showing binary, ternary, and quaternary possibilities for polymers and surfactants. Other solubilization techniques using cyclodextrins and phospholipids are included for completeness but have a different mechanism for solubilization when compared to polymer and surfactant systems.

The red box indicates that properties can change with water or solvent content. General methods for precipitating and crystallizing a compound may be applied to prepare the various polymorphs described herein. These general methods are known to those skilled in the art of synthetic organic chemistry and pharmaceutical formulation, and are described, for example, by J. March, “Advanced Organic Chemistry: Reactions, Mechanisms and Structure ” 4^th Ed. (New York: Wiley-Interscience, 1992).

In general, a given polymorph of a compound may be obtained by direct crystallization of the compound or by crystallization of the compound followed by inter-conversion from another polymorphic form or from an amorphous form. Depending on the method by which a compound is crystallized, the resulting composition may contain different amounts of the compound in crystalline form as opposed to as an amorphous material.

Also, the resulting composition may contain differing mixtures of different polymorphic forms of the compound. Compositions comprising a higher percentage of crystalline content {e.g., forming crystals having fewer lattice defects and proportionately less glassy material) are generally prepared when using conditions that favor slower crystal formation, including slow solvent evaporation and those affecting kinetics.

Crystallization conditions may be appropriately adjusted to obtain higher quality crystalline material as necessary. Thus, for example, if poor crystals are formed under an initial set of crystallization conditions, the solvent temperature may be reduced and ambient pressure above the solution may be increased relative to the initial set of crystallization conditions in order to slow down crystallization. Precipitation of a compound from solution, often affected by rapid evaporation of solvent, is known to favor the compound forming an amorphous solid as opposed to crystals. A compound in an amorphous state may be produced by rapidly evaporating solvent from a solvated compound, or by grinding, pulverizing or otherwise physically pressurizing or abrading the compound while in a crystalline state.

Seven crystalline forms and one amorphous solid were identified by conducting a polymorph screen (Example 3). Described herein are Form A, Form B, Form C, Form D, Form E, Form F, Form G, and Amorphous Form of Compound I. Where possible, the results of each test for each different polymorph are provided. Forms A, C, D and E were prepared as pure forms. Forms B, F, and G were prepared as mixtures with Form A.
Various tests were performed in order to physically characterize the polymorphs of Compound I including X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), hot stage microscopy, Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectrometry, linked thermogravimetric-infrared spectroscopy (TG-IR), solution proton nuclear magnetic resonance (¹H-NMR), solid state ¹³carbon nuclear magnetic resonance (¹³C-NMR), and moisture sorption and desorption analysis (M S/Des).

Salt screening

Physicochemical properties of drug substances, such as solubility, dissolution rate, and physicochemical stability can be altered significantly by salt formation. Consequently, important properties of the drug product such as bioavailability or shelve life can be radically influenced. Crystallics’ technology platform for crystallization screening accommodates salt screening studies using only minimal amounts of drug substance while still performing a large number of experiments. High-throughput salt screening is used for both early phase salt selection studies and broad patent protection.

Salt selection – A powerful strategy for crystal form optimization

Pharmaceutical developers have focused efforts on finding and formulating a thermodynamically stable crystalline form with acceptable physical properties for a given compound. This is reasonable, given the need to avoid cascading from a meta-stable form to a more stable one in unpredictable fashion.

Occasionally certain physical properties, such as low aqueous solubility, are limiting to performance of the compound, leading to poor oral bioavailability or insufficient solubility for an injection formulation. One of the main strategies used to affect physical performance of a compound and one that is often employed by pharmaceutical scientists is the practice of salt selection (23). At least half of compounds in marketed products are in the form of a salt for one reason or another.

This fact alone speaks to the versatility of the salt selection approach. Salt forms of a pharmaceutical can have many benefits, such as improved stability characteristics, optimal bioavailability and aqueous solubility for an injectable formulation. Salts, like all other crystalline forms, are subject to polymorphism and solvate formation, thus requiring the same form identification studies as are needed for a neutral compound.

A remarkable example of co-optimization of properties is indinavir (HIV protease inhibitor), which is marketed as the sulfate salt ethanol solvate (24,25) The crystalline free base has variable oral bioavailability in dogs (26,27) and humans (28). While acidic solutions of the base compound showed good oral pharmacokinetics, the stability of the drug in acidic solution is not consistent with a product (26). Therefore, the discovery of the salt form ensured both shelf stability and robust bioavailability performance. The salt selection strategy is limited in two ways.

First, salt formation relies on the presence of one or more ionizable functional groups in the molecule; many drugs and development compounds lack this feature.

Second, our ability to predict a priori whether a given compound will form a crystalline salt (or salts) is non-existent. The ability to actively identify crystalline salt forms has been confined to manual empirical evaluation using multiple salt formers for a given acid or base. Recently advances have been made in the area of high-throughput salt selection and crystal engineering strategies associated with salt formation (14,29-32).

In one case, we have advocated the simultaneous assessment of polymorphism as a way to help rank the developability of different crystalline salts (14). While salt forms will continue to have a prominent place in pharmaceutical science, the need for enhanced productivity dictates that every advantage must be sought to aid the design of an appropriate crystalline form of an active molecule.

Specifically, the ability to design scaffolds into crystalline forms will enhance our capacity to convert interesting molecules into effective drugs. Crystal engineering offers some additional tools in this regard. 

CASE STUDY FORM A ONLY US8084605

TRELAGLIPTIN SUCCINATE

Form A may be prepared by crystallization from the various solvents and under the various crystallization conditions used during the polymorph screen (e.g., fast and slow evaporation, cooling of saturated solutions, slurries, and solvent/antisolvent additions). Tables B and C of Example 3 summarize the procedures by which Form A was prepared.

For example, Form A was obtained by room temperature slurry of an excess amount of Compound I in acetone, acetonitrile, dichloromethane, 1,4-dioxane, diethyl ether, hexane, methanol, isopropanol, water, ethylacetate, tetrahydrofuran, toluene, or other like solvents on a rotating wheel for approximately 5 or 7 days.

The solids were collected by vacuum filtration, and air dried in the hood. Also, Form A was precipitated from a methanol solution of Compound I by slow evaporation (SE). Form A was characterized by XRPD, TGA, hot stage microscopy, IR, Raman spectroscopy, solution 1H-NMR, and solid state 13C-NMR. Figure 1 shows a characteristic XRPD spectrum (CuKa, λ=1.5418A) of Form A. The XRPD pattern confirmed that Form A was crystalline. Major X-Ray diffraction lines expressed in °2Θ and their relative intensities are summarized in Table 1. Table 1. Characteristic XRPD Peaks (CuKa) of Form A

The above set of XRPD peak positions or a subset thereof can be used to identify Form A. One subset comprises peaks at about 11.31, 11.91, 12.86, 14.54, 15.81, 16.83, 17.59, 19.26, 19.52, 21.04, 22.32, 26.63, and 29.87 °2Θ. Another subset comprises peaks at about 11.31, 11.91, 19.26, 21.04, and 22.32 °2Θ; the peaks of this subset show no shoulder peaks or peak split greater than 0.2 °2Θ. Another subset comprises peaks at about 11.31, 11.91 and 22.32 °2Θ. Figure 2 is a TGA thermogram of Form A. TGA analysis showed that Form A exhibited insignificant weight loss when heated from 25 0C to 165 0C; this result is indicative that Form A was an anhydrous solid. Figure 3 shows a characteristic DSC thermogram of Form A. DSC analysis showed a single endothermic event occurred at approximately 195 0C (peak maximum). This endothermic event was confirmed by hot stage microscopy which showed the melting of Form A, which onset around 177 0C and the melting point estimated to be at approximately 184 0C. 

US8084605

Figure 4 (A-D) shows a characteristic FT-IR spectrum of Form A. The major bands expressed in reciprocal wavelengths (wavenumber in cm”1) are positioned at about 3815, 3736, 3675, 3460, 3402, 3141, 3098, 3068, 3049, 2953, 2934, 2854, 2760, 2625, 2536, 2481, 2266, 2225, 2176, 1990, 1890, 1699, 1657, 1638, 1626, 1609, 1586, 1553, 1517, 1492, 1478, 1450, 1419, 1409, 1380, 1351, 1327, 1289, 1271, 1236, 1206, 1180, 1158, 1115, 1087, 1085, 1064, 1037, 1027, 971, 960, 951, 926, 902, 886, 870, 831, 820, 806, 780, 760, 740, 728, 701, 685, 668, 637, 608, 594, 567, 558, and 516 cm”1 (values rounded to the nearest whole number). This unique set of IR absorption bands or a subset thereof can be used to identify Form A.

One such subset comprises absorption bands at about 3141, 3098, 3068, 3049, 2953, 2934, 2854, 2266, 2225, 1699, 1657, 1609, 1586, 1553, 1517, 1492, 1478, 1450, 1380, 1351, 1327, 1236, 1206, 1115, 1063, 902, 886, 870, 820, 780, 760, 685, 608, 594, and 516 cm 1. Another subset comprises absorption bands at about 3141, 2953, 2934, 2854, 2266, 2225, 1699, 1657, 1450, 1206, 886, 760, 685, 594, and 516 cm 1. Yet another subset comprises absorption bands at about 3141, 2953, 2934, 2266, 1699, 1657, 1450, and 1206 cm 1.

Aprepitant case study FTIR.. READING MATERIAL http://alpha.chem.umb.edu/chemistry/ch361/spring%2005/ftir%20polymorph.pdf

Figure 5 (A-D) shows a characteristic Raman spectrum of Form A. The major Raman bands expressed in reciprocal wavelengths (wavenumber in cm”1) are positioned at about 3100, 3068, 3049, 2977, 2954, 2935, 2875, 2855, 2787, 2263, 2225, 2174, 1698, 1659, 1626, 1607, 1586, 1492, 1478, 1451, 1439, 1409, 1400, 1382, 1351, 1328, 1290, 1281, 1271, 1237, 1223, 1213, 1180, 1155, 1134, 1115, 1084, 1063, 1035, 971, 952, 926901, 868, 805, 780, 759, 740, 727, 701, 686, 669, 609, 594, 566, 558, 516, 487, 479, 433, 418, 409, 294, 274, 241, 218, 191 and 138 cm”1 (values rounded to the nearest whole number). This unique set of Raman bands or a subset thereof may be used to identify Form A.

One such subset comprises Raman bands at about 2954, 2935, 2225, 1698, 1659, and 1607 cm”1. Another subset comprises Raman bands at about 3068, 2954, 2935, 2225, 1698, 1659, 1607, 1586, 1223, 1180, 901, 780, 759, 669, and 516 cm”1. Yet another subset comprises Raman bands at about 3100, 3068, 2225, 1698, 1659, 1607, 1586, 1351, 1237, 1223, 1180, 1155, 1134, 1115, 1063, 952, 926, 901, 868, 805, 780, 759, 740, 669, 609, and 516 cm”1.

Form A was further characterized by solution 1H NMR and solid-state 13carbon NMR. The spectra are reported in Figures 6 and 7, respectively. Chemical assignments were not performed; however, the spectra are consistent with the known chemical structure of Compound I. US8084605

 Example 11. Characterization of Form A Material prepared by the procedure of Example 1 was designated as Form A. The material was characterized by XRPD, TGA, DSC, hot stage microscopy, FT-IR, FT- Raman, ¹H NMR, and ¹³C NMR. The analyses were conducted according to the procedures outlined in Section B of Example 3.

The characteristic spectra and thermograms for Form A are reported in Figures 1-7. The characterization data are summarized in Table D. Table D. Characterization Data of Form A of Compound I US8084605

Amorphous solid dispersion screening

Using the amorphous form of a drug substance offers several advantages with respect to dissolution rate and solubility of the substance. However, reduced chemical stability, increased hygroscopicity and, most important, physical instability are the major drawbacks of using the amorphous phase in the final drug product. These drawbacks can be overcome by stabilizing the amorphous phase of the API in a polymer matrix, e.q. an amorphous solid dispersion. Amorphous phases dissolve more rapidly than crystalline forms, and can significantly increase bioavailability of poorly water soluble drugs substances. However, the use of amorphous materials requires confidence that crystallization will not occur during the product lifespan. For a material that has never been obtained in a crystalline form, focus should be put on attempting to crystallize it. Crystallics has extensive experience of obtaining crystalline phases from amorphous materials.

Dispersions of a drug substance onto a polymeric matrix has received increased attention in recent years. A successful dispersion results in an amorphous solid material and will show improved dissolution rates and higher apparent solubility characteristics, as well as, sufficient resistance to chemical degradation and should be physically stable e.q. sufficient high glass transition temperature avoiding crystallization of the API.

A variety of factors contribute to the formation of a suitable Amorphous Solid Dispersion (ASD), including the nature of the polymer, the drug polymer ratio, the impact of surfactants and the solvent used in the process. Crystallics has developed high-throughput solid dispersion screening technology in order to find the optimal combination of these factors.

Example 10. Preparation of Amorphous Form US8084605

A sample of Compound I (40 mg) was dissolved in 1000 μl of water. The solution was filtered through a 0.2 μm nylon filter into a clean vial then frozen in a dry ice/acetone bath. The vials were covered with a Kimwipe then placed on a lyophilizer overnight. The resulting solids yielded Amorphous Form. 8. Amorphous Form The Amorphous Form of Compound I was prepared by lyophilization of an aqueous solution of Compound I (Example 10). The residue material was characterized by XRPD and the resulting XRPD spectrum displayed in Figure 26. The XRPD spectrum shows a broad halo with no specific peaks present, which confirms that the material is amorphous. The material was further characterized by TGA, DSC, hot stage microscopy, and moisture sorption analysis. 

TGA analysis (Figure 27) showed a 1.8% weight loss from 25 ⁰C to 95 ⁰C, which was likely due to loss of residual solvent. 

DSC analysis (Figure 28) showed a slightly concave baseline up to an exotherm at 130 ⁰C (recrystallization), followed by an endotherm at 194 ⁰C, which results from the melting of Form A. Hot stage microscopy confirmed these recrystallization and melting events (micrographs not included). An approximate glass transition was observed (Figure29) at an onset temperature of 82 ⁰

C. 

Moisture sorption/desorption data (Figure 30 and Example 25) showed a 1.0% weight loss on equilibration at 5% relative humidity. Approximately 8% of weight was gained up to 65% relative humidity. Approximately 7% of weight was lost at 75% relative humidity. This is likely due to the recrystallization of the amorphous material to a crystalline solid. A 4.4% weight gain was observed on sorption from 75% to 95% relative humidity. Approximately 4.7% weight was lost on desorption from 95% to 5% relative humidity. 

The solid material remaining after the moisture sorption analysis was determined to be Form A by XRPD (Figure 31). Table H. Characterization Data of Amorphous Form US8084605

T=temperature, RH=relative humidity, MB = moisture sorption/desorption analysis Example 19: Relative Humidity Stressing Experiments

 Moisture Sorption/Desorption Study of Amorphous Form.

Mositure sorption and desorption study was conducted on a sample of Amorphous Form. The sample was prepared by lyophilolization of a solution of Compound I in water (Example 3, section A.9). The mositure sorption and desorption study was conducted according to the procedures outlined in Example 3, section B.10. The data collected is plotted in Figure 29 and summarized in Table N .Table N. Moisture Sorption/Desorption of Amorphous Form

Table B. Crystallization Experiments of Compound I from Solvents

a) FE = fast evaporation; SE = slow evaporation; RT = room temperature; SC = slow cool; CC = crash cool, MB = moisture sorption/desorption analysis b) qty = quantity; PO = preferred orientation Table C. Crystallization Experiments of Compound I in Various Solvent/Antisolvent

a precipitated by evaporation of solvent Table A. Approximate Solubilities of Compound I US8084605

a) Approximate solubilities are calculated based on the total solvent used to give a solution; actual solubilities may be greater because of the volume of the solvent portions utilized or a slow rate of dissolution. Solubilities are reported to the nearest mg/mL.

Example 3.

Polymorph Screen Compound I as prepared by the method described in Example 1 was used as the starting material for the polymorph screen. Solvents and other reagents were of ACS or HPLC grade and were used as received. A. Sample Generation. Solids for form identification were prepared via the following methods from Compound I.

1. Fast Evaporation (FE) A solution of Compound I was prepared in test solvents. The sample was placed in the hood, uncovered, to evaporate under ambient conditions. The solids were analyzed by XRPD for form identification.

2. Slow Evaporation (SE) A solution of Compound I was prepared in test solvents. The sample was placed in the hood, covered with foil rendered with pinholes, to evaporate under ambient conditions. The solids were analyzed by XRPD for form identification.

3. Room Temperature (RT) Slurries An excess amount of Compound I was slurried in test solvent on a rotating wheel for approximately 5 or 7 days. The solids were typically collected by vacuum filtration, air dried in the hood, and analyzed by XRPD for form identification.

4. Elevated Temperature Slurries Excess Compound I was slurried in test solvents at 47 ⁰C on a shaker block for approximately 5 days. The solids were collected by vacuum filtering, dried in the hood, and then analyzed by XRPD for form identification.

5. Slow Cooling Crystallization (SC)

A saturated or near saturated solution of Compound I was prepared at elevated temperature. The samples were filtered through warmed 0.2 μm filters into warmed vials. The heat source was turned off and the samples slowly cooled to ambient temperature. If precipitation did not occur within a day the samples were placed in the refrigerator. The samples were transferred to a freezer if precipitation did not occur within several days. The solids were collected by decanting the solvent or vacuum filtration, dried in the hood and analyzed by XRPD for form identification.

6. Crash Cooling Crystallization (CC) A saturated or near saturated solution of Compound I was prepared at elevated temperature. The samples were filtered through warmed 0.2 μm filters into warmed vials then rapidly cooled in an acetone/dry ice or ice bath. If precipitation did not occur after several minutes the samples were placed in the refrigerator or freezer. Solids were collected by decanting solvent or vacuum filtration, dried in the hood, and then analyzed by XRPD. Samples that did not precipitate under subambient conditions after several days were evaporated in the hood and analyzed by XRPD for form identification.

7. Solvent/Antisolvent Crystallization (S/AS) A solution of Compound I was prepared in test solvent. A miscible antisolvent was added with a disposable pipette. Precipitate was collected by vacuum filtration or decanting solvent. The samples were stored under subambient conditions if precipitation did not occur. If solids were not observed after several days the samples were evaporated in the hood. Collected solids were analyzed by XRPD for form identification.

8. Relative Humidity (RH) Stressing Experiments Samples of Compound I were placed uncovered in approximately 58%, 88%, and 97% relative humidity jars. The samples were stored in the jars for approximately 8 days. The solids were collected and analyzed by XRPD for form identification.

9. Lyophilization Compound I was dissolved in water in a glass vial. The solution was frozen by swirling the vial in an acetone/dry ice bath. The frozen sample was placed on the lyophilizer until all of the frozen solvent was removed. The solids were collected and analyzed by XRPD for form identification.

10. Grinding Experiments Aliquots of Compound I were ground manually with a mortar and pestle as a dry solid and a wet paste in water. The samples were ground for approximately three minutes. The solids were collected and analyzed by XRPD for form identification.

11. Dehydration Experiments Hydrated samples of Compound I were dehydrated at ambient conditions (2 days) and in an ambient temperature vacuum oven (1 day). The solids were collected and analyzed by XRPD for form identification.

12. Vapor Stress Experiments Amorphous Compound I was placed in acetone, ethanol, and water vapor chambers for up to eight days. The solids were collected and analyzed by XRPD for form identification.

STABILITY STUDY Stability studies are commonly performed for new drug entities with chemical stability and impurity formation being investigated. It is also important to monitor the physical stability under these same conditions to anticipate any form changes that may occur. As an example, many hydrates will dehydrate to a lower hydrate or anhydrous form at elevated temperatures. Anhydrous materials can also undergo form transformations to other anhydrous forms upon heating.

These types of changes can be monitored using heating studies in an oven with subsequent XRPD analysis or in-situ variable temperature XRPD can be used to look for changes. In other cases, anhydrates will convert to hydrates or the API in an amorphous solid dispersion may crystallize under elevated relative humidity (RH) conditions.

Equilibration in RH chambers with subsequent analysis by XRPD or in-situ variable RH XRPD experiments can be used to readily identify these form changes. Once the effect of temperature and RH on form changes is understood, this can be factored into other processes such as drying, formulation, storage, and packaging B. Sample Characterization. The following analytical techniques and combination thereof were used determine the physical properties of the solid phases prepared.

1. X-Ray Powder Diffraction (XRPD)

XRPD is commonly used as the initial method of analysis for form screens. For polymorph, salt, and co-crystal screens XRPD is used to determine if a new form has been produced by comparing the powder pattern to all known forms of the API and the counterion/guest. If a new form is found by XRPD, additional characterization by other methods is in order. For amorphous solid dispersion screens, XRPD is used to confirm a lack of crystallinity indicated by an amorphous halo in the powder pattern.

The halos will move depending on the concentration and interactions of the API and polymer. Computational methods have also been used with XRPD data to establish miscibility of amorphous solid dispersions X-ray powder diffraction is a front line technique in solid form screening and selection based on its ability to give a fingerprint of the solid-state structure of a pharmaceutical material. Understanding the solid forms of a pharmaceutical compound provides a road map to help direct a variety of development activities ranging from crystallization, formulation, packaging, storage, and performance.

Different screening and selection strategies are warranted in early and late development because different information is needed at the various stages. Solid form selection and formulation approaches need to be investigated together and tailored to the situation. It is important to include solid form selection and possible changes in form as part of the risk management strategy throughout the drug development process.

X-ray powder diffraction (XRPD) analyses were performed using an Inel XRG- 3000 diffractometer equipped with a CPS (Curved Position Sensitive) detector with a 2Θ (2Θ) range of 120°. Real time data were collected using Cu-Ka radiation starting at approximately 4 °2Θ at a resolution of 0.03 °2Θ. The tube voltage and amperage were set to 40 kV and 30 mA, respectively. The pattern is displayed from 2.5 to 40 °2Θ. Samples were prepared for analysis by packing them into thin- walled glass capillaries. Each capillary was mounted onto a goniometer head that is motorized to permit spinning of the capillary during data acquisition. The samples were analyzed for approximately 5 minutes.

Instrument calibration was performed using a silicon reference standard. Peak picking was performed using the automatic peak picking in the Shimadzu XRD-6000 Basic Process version 2.6. The files were converted to Shimadzu format before performing the peak picking analysis. Default parameters were used to select the peaks.

2. Thermogravimetric Analysis (TGA)

Thermogravimetric (TG) analyses were performed using a TA Instruments 2950 thermogravimetric analyzer. Each sample was placed in an aluminum sample pan and inserted into the TG furnace. The furnace was first equilibrated at 25 ⁰C, then heated under nitrogen at a rate of 10 °C/min, up to a final temperature of 350 ⁰C. Nickel and Alumel™ were used as the calibration standards.

3. Differential Scanning Calorimetry (DSC)

Differential scanning calorimetry (DSC) was performed using a TA Instruments differential scanning calorimeter 2920. The sample was placed into an aluminum DSC pan, and the weight accurately recorded. The pan was covered with a lid and then crimped. The sample cell was equilibrated at 25 ⁰C and heated under a nitrogen purge at a rate of 10 °C/min, up to a final temperature of 350 ⁰C. Indium metal was used as the calibration standard. Reported temperatures are at the transition maxima. For studies of the glass transition temperature (T_g) of the amorphous material, the sample cell was equilibrated at ambient temperature, then heated under nitrogen at a rate of 20 °C/min, up to 100 ⁰C. The sample cell was then allowed to cool and equilibrate at -20 ⁰C. It was again heated at a rate of 20 °C/min up to 100 ⁰C and then cooled and equilibrated at -20 ⁰C. The sample cell was then heated at 20 °C/min up to a final temperature of 350 ⁰C. The T_g is reported from the onset point of the transition.

4. Hot Stage Microscopy.

Hot stage microscopy was performed using a Linkam hot stage (model FTIR 600) mounted on a Leica DM LP microscope. The samples were prepared between two cover glasses and observed using a 20χ objective with crossed polarizers and first order compensator. Each sample was visually observed as the stage was heated. Images were captured using a SPOT Insight™ color digital camera with SPOT Software v. 3.5.8. The hot stage was calibrated using USP melting point standards.

5. Thermogravimetric-Infrared (TG-IR)

Thermogravimetric infrared (TG-IR) analyses were acquired on a TA Instruments thermogravimetric (TG) analyzer model 2050 interfaced to a Magna 560^® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet) equipped with an Ever-Glo mid/far IR source, a potassium bromide (KBr) beamsplitter, and a deuterated triglycine sulfate (DTGS) detector. The TG instrument was operated under a flow of helium at 90 and 10 cc/min for the purge and balance, respectively. Each sample was placed in a platinum sample pan, inserted into the TG furnace, accurately weighed by the instrument, and the furnace was heated from ambient temperature to 250 ⁰C at a rate of 20 °C/min.

The TG instrument was started first, immediately followed by the FT-IR instrument. Each IR spectrum represents 32 co-added scans collected at a spectral resolution of 4 cm^“1. A background scan was collected before the beginning of the experiment. Wavelength calibration was performed using polystyrene. The TG calibration standards were nickel and Alumel™. Volatiles were identified from a search of the High Resolution Nicolet TGA Vapor Phase spectral library.

6. Fourier Transform Infrared Spectroscopy (FT-IR)

Infrared spectra were acquired on a Magna-IR 560^® or 860^® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet) equipped with an Ever-Glo mid/far IR source, an extended range potassium bromide (KBr) beamsplitter, and a deuterated triglycine sulfate (DTGS) detector. A diffuse reflectance accessory (the Collector™, Thermo Spectra-Tech) was used for sampling. Each spectrum represents 256 co-added scans collected at a spectral resolution of 4 cm^“1. Sample preparation consisted of physically mixing the sample with KBr and placing the sample into a 13 -mm diameter cup. A background data set was acquired on a sample of KBr. A Log 1/R (R = reflectance) spectrum was acquired by taking a ratio of these two data sets against each other. Wavelength calibration was performed using polystyrene. Automatic peak picking was performed using Omnic version 7.2.

7. Fourier Transform Raman Spectroscopy (FT-Raman)

FT-Raman spectra were acquired on a Raman accessory module interfaced to a Magna 860^® Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet). This module uses an excitation wavelength of 1064 nm and an indium gallium arsenide (InGaAs) detector. Approximately 0.5 W of Nd)YVO₄ laser power was used to irradiate the sample. The samples were prepared for analysis by placing the material in a glass tube and positioning the tube in a gold-coated tube holder in the accessory. A total of 256 sample scans were collected from at a spectral resolution of 4 cm^“1, using Happ-Genzel apodization. Wavelength calibration was performed using sulfur and cyclohexane. Automatic peak picking was performed using Omnic version 7.2.

8. Solid State Nuclear Magnetic Resonance Spectroscopy (¹³C-NMR)

The solid-state ¹³C cross polarization magic angle spinning (CP/MAS) NMR spectrum was acquired at ambient temperature on a Varian ^UN1TYINOVA-400 spectrometer (Larmor frequencies: ¹³C = 100.542 MHz, ¹H = 399.799 MHz). The sample was packed into a 4 mm PENCIL type zirconia rotor and rotated at 12 kHz at the magic angle. The spectrum was acquired with phase modulated (SPINAL-64) high power ¹H decoupling during the acquisition time using a ¹H pulse width of 2.2 μs (90°), a ramped amplitude cross polarization contact time of 5 ms, a 30 ms acquisition time, a 10 second delay between scans, a spectral width of 45 kHz with 2700 data points, and 100 co-added scans. The free induction decay (FID) was processed using Varian VNMR 6.1C software with 32768 points and an exponential line broadening factor of 10 Hz to improve the signal-to- noise ratio. The first three data points of the FID were back predicted using the VNMR linear prediction algorithm to produce a flat baseline. The chemical shifts of the spectral peaks were externally referenced to the carbonyl carbon resonance of glycine at 176.5 ppm. 9. Solution Nuclear Magnetic Resonance Spectroscopy (¹H-NMR) The solution ¹H NMR spectrum was acquired at ambient temperature with a

spectrometer at a ¹H Larmor frequency of 399.803 MHz. The sample was dissolved in methanol. The spectrum was acquired with a ¹H pulse width of 8.4 μs, a 2.50 second acquisition time, a 5 second delay between scans, a spectral width of 6400 Hz with 32000 data points, and 40 co-added scans. The free induction decay (FID) was processed using Varian VNMR 6.1C software with 65536 points and an exponential line broadening factor of 0.2 Hz to improve the signal-to-noise ratio. The spectrum was referenced to internal tetramethylsilane (TMS) at 0.0 ppm. 10.

Moisture Sorption/Desorption Analysis Moisture sorption/desorption data were collected on a VTI SGA-100 Vapor Sorption Analyzer. Sorption and desorption data were collected over a range of 5% to 95% relative humidity (RH) at 10% RH intervals under a nitrogen purge. Samples were not dried prior to analysis. Equilibrium criteria used for analysis were less than 0.0100% weight change in 5 minutes, with a maximum equilibration time of 3 hours if the weight criterion was not met. Data were not corrected for the initial moisture content of the samples. NaCl and PVP were used as calibration standards

Does solid form matter? 

Sometimes the properties of two solid forms of a drug are quite similar. In other cases, the physical and chemical properties can vary dramatically and have great impact on pharmacokinetics, ease of manufacturing, and dosage form stability. Properties that can differ among solid forms of a substance include color, solubility, crystal shape, water sorption and desorption properties, particle size, hardness, drying characteristics, flow and filterability, compressibility, and density.

Different solid forms can have different melting points, spectral properties, and thermodynamic stability. In a drug substance, these variations in properties can lead to differences in dissolution rate, oral absorption, bioavailability, levels of gastric irritation, toxicology results, and clinical trial results. Ultimately both safety and efficacy are impacted by properties that vary among different solid forms. Stability presents a special concern, since it’s easy to inadvertently generate the wrong form at any point in the development process.

Because energy differences between forms are usually relatively small, form interconversion is common and can occur during routine API manufacturing operations and during drug product formulation, storage, and use. The stakes are high. Encountering a new solid form during late stages of development can delay filing. A new form appearing in drug product can cause product withdrawal.  

When should a search for solid forms begin?

The key to speed in the drug development process is to do it right the first time. For solid pharmaceuticals, that means:

• identify the optimum solid form early in drug development
• make the same form for clinical material and commercial API
• develop a crystallization process that assures control of solid form
• produce a drug product with solid form stability through expiration

scientists strongly recommend that investigation of possible solid forms of a new chemical entity be carried out as early in the development process as drug supply will allow. The best approach has three stages. The first stage, more relevant to some development processes than to others, is a milligram-scale abbreviated screen on efficacious compounds prior to final IND candidate selection. This early information can be used to guide selection of salts and solid forms for scale-up and toxicology studies. The second stage is full polymorph screening and selection of optimum solid form. This stage is important to all development processes and should certainly occur before the first GMP material is produced. In the case of ionic drugs, various salts should be prepared and screened for polymorphs and hydrates. The third stage, an exhaustive screen carried out before drug launch, is an effort to find and patent all of the forms of a high-potential drug. Staging the screening in this way optimizes the balance among the factors of early knowledge of options, probability of commercial success, and judicious investment of R&D money.

Delay in understanding solid form issues results in problems like different batches of clinical material having different solid forms. Another common and preventable dilemma arises when clinical trials are carried out with one form while commercial production generates another. In this case, bridging studies are required to demonstrate to regulatory agencies that the clinicals are relevant. ICH guidelines require a search for solid forms, comparison of properties that might affect product efficacy, and, if appropriate, setting of solid form specifications.

How is solid form controlled in API manufacture? 

It is important to control solid form during API synthesis in order to demonstrate complete process control to regulatory agencies. Different solid forms can have different solubilities and can affect recovery of API. Purification efficiencies can vary due to differential exclusion of impurities. Filtration and transfer characteristics often differ between forms. Ease of drying can vary due to different abilities to bind solvent and water in the crystal lattice. A prevalent but incorrect belief is that solid form is determined primarily by choice of crystallization solvent. In fact, it is well established that parameters like temperature, supersaturation level, rate of concentration or cooling, seeding, and ripening can have an overriding effect. These variables must be controlled to ensure consistency of solid form in API.

Can solid form problems arise in drug products, too? 

The potential for solid form variation does not end at API production. Solid form issues remain through formulation, manufacture, storage, and use of drug product. It is common to observe form transformation during standard manufacturing operations like wet granulation and milling. Excipient interactions and compaction can induce form changes. Changes can occur in the final dosage form over time. Suspensions, including those in transdermal patches, are particularly vulnerable because they provide a low-energy pathway (dissolution/recrystallization) for form interconversion. Lyophile cakes are normally amorphous, but can crystallize on storage leading to difficulty in reconstitution. Even products containing drug in solution, such as filled gel caps, can be affected if the solution is or becomes supersaturated with respect to one of the possible solid forms of the drug.

How can you tell when you have a solid form problem? 

Whenever there is a specification failure in drug product or drug substance, solid form changes should be considered in the search for causes. Particularly symptomatic is failure to meet melting point or dissolution specifications. Changes in humidity, crystallization conditions, or crystallization solvent can produce unwanted forms. Solvents known to readily produce solvates include water, alcohols, chlorinated hydrocarbons, cyclic ethers, ketones, nitriles, and amides. Changes in the appearance of gel caps or cracking of tablet coatings can indicate solid form problems. Various solid-state analytical techniques can be used to identify solid form in API. Some techniques can even determine solid form of API in intact final dosage form. Among the most useful techniques for solid-state characterization are melting point, DSC, TGA, hot stage and optical microscopy, solid-state NMR, IR and Raman spectroscopy, and X-ray powder diffraction.

Is there any good news about polymorphism? 

Polymorphism presents opportunities as well as challenges. Investigation of the properties of different forms of a commercial drug can lead to new products with improved onset time, greater bioavailability, sustained release properties, or other therapeutic enhancements. New forms can bring improvements in manufacturing costs or API purity. These improvements are patentable and can provide a competitive advantage. An underutilized potential of polymorphism is to solve formulation problems that cause the abandonment of potentially useful drugs in which much investment has already been made. 

SOLUBILITY

Solubility is an important parameter for new molecules especially with the emergence of many poorly soluble compounds in the drug discovery and development pipeline. Polymorphic forms can exhibit solubility differences that vary within a factor of 1-5, amorphous solid dispersions show an improvement one or two orders of magnitude higher, and salts and co-crystals fall between these extremes . A comparison of solubility values of pure forms will provide important information when deciding on a solid form or dosage form. X-ray powder diffraction will allow identification of pure forms for these types of measurements.

However, form changes during solubility and dissolution experiments are also possible and need to be investigated. Solids remaining at the end of solubility and dissolution experiments should always be analyzed initially by XRPD to determine if a form transformation has occurred under these conditions. If a form change has occurred, XRPD patterns can be compared to known forms (polymorphs, hydrates, salts, free acid/base) in order to identify the solids remaining. If a pattern is obtained that does not correspond to known forms, complementary methods will be needed to determine properties such as hydration state or a change in stoichiometry as would be observed from breaking a salt and forming the free acid/base or the formation of salts in buffered solutions.

FORMULATION

Formulators are charged with the responsibility to formulate a product which is physically and chemically stable, manufacturable, and bioavailable. Most drugs exhibit structural polymorphism, and it is preferable to develop the most thermodynamically stable polymorph of the drug to assure reproducible bioavailability of the product over its shelf life under a variety of real-world storage conditions. There are occasional situations in which the development of a metastable crystalline or amorphous form is justified because a medical benefit is achieved. Such situations include those in which a faster dissolution rate or higher concentration are desired, in order to achieve rapid absorption and efficacy, or to achieve acceptable systemic exposure for a low-solubility drug.

Another such situation is one in which the drug remains amorphous despite extensive efforts to crystallize it. If there is no particular medical benefit, there is less justification for accepting the risks of intentional development of a metastable crystalline or amorphous form. Whether or not there is medical benefit, the risks associated with development of a metastable form must be mitigated by laboratory work which provides assurance that (a) the largest possible form change will have no substantive effect on product quality or bioavailability, and/or (b) a change will not occur under all reasonable real-world storage conditions, and/or (c) analytical methodology and sampling procedures are in place which assure that a problem will be detected before dosage forms which have compromised quality or bioavailability can reach patients.

Crystal engineering and co-crystals

Crystal engineering is generally considered to be the design and growth of crystalline molecular solids with the aim of impacting material properties. A principal tool is the hydrogen bond, which is responsible for the majority of directed intermolecular interactions in molecular solids. Co-crystals are multi-component crystals based on hydrogen bonding interactions without the transfer of hydrogen ions to form salts – this is an important feature, since Brønsted acid-base chemistry is not a requirement for the formation of a co-crystal.

Co-crystallization is a manifestation of directed self-assembly of different components. Co-crystals have been described of various organic substances over the years (33,34) and given various names, such as addition compounds (35,36) molecular complexes (37,38) and heteromolecular co-crystals (39). Regardless of naming convention, the essential meaning is that of a multi-component crystal where no covalent chemical modification of the constituents occurs as a result of the crystal formation. Pharmaceuticals co-crystals have only recently been discussed as useful materials for drug products.  

Pharmaceutical co-crystals

Pharmaceutical co-crystals can be defined as crystalline materials comprised of an active pharmaceutical ingredient (API) and one or more unique co-crystal formers, which are solids at room temperature. Co-crystals can be constructed through several types of interaction, including hydrogen bonding, p-stacking, and van der Waals forces. Solvates and hydrates of the API are not considered to be co-crystals by this definition. However, co-crystals may include one or more solvent/water molecules in the crystal lattice. An example of putative design, a construction and preparation process is shown in Figure 2 for the 5-fluororuracil:urea 1:1 co-crystal(40).

This real example neatly illustrates the opportunity and challenge that exists currently with designing pharmaceutical co-crystals. Firstly, the ‘design’ is challenging because we have no ability to predict the exact crystal structure that may result from a crystallization attempt. By analogy to the challenge of deriving protein structure from first principles, the primary sequence (chemical structure in our case) is known and elements of secondary structure (the 2-D tape construction in Figure 2) are somewhat discernible from primary information. Prediction of the actual 3-D folded conformation (tertiary structure or obtained by self-assembly) is not possible. In other words, while we currently have the ability to project which things associate in what approximate manner on the secondary level, crystal structure prediction is essentially an intractable proposition.

By extension, and just as the exact function of a protein and quantitative parameters of activity are not predictable from primary and secondary structure, the prediction of crystal properties is not possible in the absence of structural information and measurements. There is early evidence that practitioners were aware that apparent co-crystallization of drugs could lead to useful preparations (41). In fact, a ‘chemical compound’ composed of sulfathiazole and proflavin dubbed flavazole was used to treat bacterial infection during the Second World War (42).

The case of flavazole reveals insight into how two different molecules might interact in a putative co-crystal:“… flavazole is definitely a chemical compound containing equimolar proportions of sulphathiazole and proflavin base. It is believed that combination occurs through the acidic sulphonamide group (SO2NH) of the sulphathiazole and the basic centres of the proflavin. Perhaps the most realistic expression of the formula would be to place proflavin and sulphathiazole side by side with a comma between them.” (42)  In the second half of the 20th century, interest in co-crystals evolved into the directed study of intermolecular interactions in crystalline solids (43-45). The technical development of routine single-crystal structure determination led to a watershed of data, now largely accessible through the Cambridge Structural Database (CSD) (46,47).

The structural data have become useful for understanding the intermolecular interactions in co-crystals in atomic level detail (48). Using insight gained from analysis of the CSD and directed experimentation, scientists attempt design of co-crystals with specific properties, such as color or non-linear optical response, by selecting starting components with appropriate molecular properties likely to exhibit specific intermolecular interactions in a crystal (49-52).

However, even when chemically compatible functional groups are present it is not possible to accurately predict if a co-crystal, a eutectic mixture or simply a physical mixture will result from any given experiment. As a result of these complexities, attention has been directed at the identification and characterization of intermolecular packing motifs with the goal of developing principles for co-crystal materials (53).

Figure 2.  Steps involved in crystal engineering of a pharmaceutical phase, exemplified by the real example of co-crystallization of 5-fluorouracil and urea. Scientists in India have reported a rare example of synthon polymorphism in co-crystals of 4,4′-bipyridine and 4-hydroxybenzoic acid.

Polymorphism is defined as the ability of a material to exist in more than one form or crystal structure. It has important implications for the properties of such materials; for example in pharmaceuticals, the dissolution rate of a drug can be dependent on the polymorphic form. While this is a common phenomenon in single crystals it is much less common in co-crystals, systems where the structure has at least two distinct components. Gautam Desiraju from the Indian Institute of Science, found that when 4,4′-bipyridine and 4-hydroxybenzoic acid were dissolved together in a solvent such as methanol they would co-crystallise to form two different polymorphs. They noticed that a third form, a pseudopolymorph, was also present.

PROSPECTS FOR CRYSTAL ENGINEERING AND PHARMACEUTICAL CO-CRYSTALS

At the beginning of the 21st century, the field of crystal engineering has experienced significant development. Importantly, crystal engineering principles are now being actively considered for application to pharmaceuticals to modulate the properties of these valuable materials (54).

Because the physical properties that influence the performance of pharmaceutical solids are reasonably well appreciated, there is a unique opportunity to apply crystal engineering techniques and the appropriate follow-up studies to solve real world problems, such as poor physical and chemical stability or inadequate dissolution for appropriate biopharmaceutical performance of an oral drug. As structures and series of pharmaceutical co-crystals have begun to appear, we again find that properties cannot be predicted from the structures.  Nevertheless, occasional trends have been suggested.

For example, insoluble drug compounds co-crystallized with highly water soluble complements tend to achieve kinetic solubilities in aqueous media several times greater than the pure form (55,56).

There are also more possible phases for each given active compound to consider, thus there will arguably be a greater opportunities for property enhancement. In terms of stability enhancement and solubilization, the example of the series of itraconazole co-crystals with pharmaceutically acceptable 1,4-diacids (55) suggests a strategy alternative to amorphous drug formulation. The co-crystal options presented retain the stability inherent in a crystalline state, while allowing for solubilization that significantly exceeds that of crystalline itraconazole base and rivals the performance of the engineered amorphous bead formulation (Sporanox®).

Where are we now? From recent literature it appears that knowledge gained over the past century and increasingly sophisticated screening techniques developed within the last decade are paving the way towards design of co-crystals with potentially improved pharmaceutical properties (55-58) In terms of the application to pharmaceutical systems, the field of crystal engineering is developing the retro-synthetic understanding of crystal structure using reasoning that is analogous to that applied by organic chemists.  For example, the retro-synthetic approach in covalent synthesis operates on the level of a single molecule, while the analogous effort in crystal engineering focuses on the “supermolecule”:

 piracetam

The assemblies that define the crystalline arrangement of the molecules as they self-organize into the solid-state. The parallels between the development of crystal engineering and synthetic organic chemistry run still deeper. Methodologies for carrying out these crystallizations are being developed alongside the development of new robust motifs (6,53,55,57,60). The importance of the solubility and dissolution relationships of the components of a putative co-crystal is becoming a matter of significant investigation (56,60). The same can be said for the roles of additives in templating novel forms.

Mechanical milling of materials has also been documented as a means to make co-crystals, and a recent example of polymorphic forms of caffeine:glutaric acid illustrates the opportunities of this type of processing to influence crystal form (61). With an increase in the understanding of the modes of self-assembly, one can start to address the design aspect towards making pharmaceutical co-crystals.

There remain several limitations to the application of what is currently known to the design of useful materials. As mentioned earlier, it remains intractable to reliably predict crystal structure.  Multi-component crystals are well out of reach for prediction due in part to complex energetic landscapes, lack of appropriate charge density models and a large number of degrees of freedom, making computation unfeasible. Moreover, there is only a qualitative understanding of the interplay between intermolecular interactions and materials performance, especially for properties relevant to pharmaceuticals such as solubility, dissolution profile, hygroscopicity and melting point.

But the saving grace of the co-crystal approach comes in two guises: Complementarity and diversity. On the topic of complementarity, it is possible, by way of CSD database mining for instance, to identify trends of hetero-synthon occurrence in model systems. As for the diversity aspect, the space of possible co-crystal formers is large, limited only by pharmaceutical acceptability. Coupled with parameters such as stoichiometry variation and increase in the number of components (binary systems can be expanded into ternary ones, etc.), the opportunities appear vast.

THE FUTURE OF CRYSTAL ENGINEERING IN PHARMACEUTICAL SCIENCE

READ

Novel Challenges in Crystal Engineering: Polymorphs and New …

Where are we going?  At this point, we have only just scratched the surface of materials science-driven pharmaceutical product design. In the 21st century, practitioners of pharmaceutical chemistry need to enumerate and exploit the opportunities of crystal form design that nature affords us, and thus gain increasing ability to design the materials we need from the molecules that we seek to convert into pharmaceuticals.

Learning will be facilitated by advances in crystallization automation (6,62), microscopy-spectroscopy techniques (Raman and IR microscopy) and new techniques such as terahertz spectroscopy and AFM, along with increasingly sophisticated X-ray diffraction lab instrumentation. In addition, further enhancements in the data mining tools associated with the CSD operating on an ever increasing number of high-quality crystal structures will undoubtedly lead to new knowledge and principles of interaction. 

The challenge placed before pharmaceutical scientists, now and in the future, is the following: (i) to understand the requirement of a particular compound in terms of materials structure and properties, and (ii) to creatively integrate crystal engineering within the limits of pharmaceutical acceptability of components to obtain new forms of active ingredients with desirable properties for formulation and delivery. It should become the collective mantra of medicinal chemists, process engineers and pharmaceutical scientists to “design and make the material we need.” This mantra can form the common aspiration for an industry that is in significant need of innovation and productivity enhancement.

Applications and Advantages

Applications

• Drug companies can use this technology to protect themselves against others generating and patenting polymorphs

Advantages

• Having more than one solid form of a drug allows optimization of drug dissolution behavior and shelf life

IP AND POLYMORPHS

In order for a new drug to enter the market, pharmaceutical companies must invest for many years in very expensive clinical trials and a lengthy regulatory approval process.Market protection plays therefore a major role in the growth of the pharmaceutical industry and Intellectual Property (IP) laws are intended to give the investors an opportunity to recover their costs. Patent filing is one way of efficiently protecting various aspects of an innovative drug.

The duration of the new drug’s market protection is, however, limited in time and once the original drug is no longer protected, legal copies (generic medicines) can be developed and marketed by competitors at more accessible prices, since the expensive basic research, as well as pre-clinical and clinical trials (at least for small molecules) are no longer necessary. Generic medicines are either identical copies of the original drug or so-called bioequivalent versions of it.

Bioequivalent means that they behave as the original drug when administered to patients. For a generic drug to be a bioequivalent its Active Pharmaceutical Ingredient (API) does not need to be the same solid form as in the original drug. A different polymorph or a pseudo-polymorph (i.e. solvate, hydrate) of the API and different excipients are acceptable variants, as long as the final generic drug product behaves as the original one.

Solid Forms Screening

Screening of solid forms, in particular polymorphs of APIs, is therefore an essential part of pharmaceutical development and lifecycle management, not only for scientific and regulatory reasons, but also because of the key role that pharmaceutical solid forms play in the area of IP, for innovators as well as for generic companies. The knowledge generated by conducting solid form screening, in fact, can provide an innovator company the opportunity to build a strong patent portfolio around different solid forms and therefore a way to maximize returns from drug development.

This allows innovator companies to gain several years of additional protection for their product after the expiry of the basic molecule patent, since various pharmaceutical solid forms are individually patentable. In the US, for instance, innovator companies are required to identify, in the so-calledOrange Book, their patents covering different solid forms performing the same as the product described in the corresponding NDA. In return, they can benefit from a 30-months stay over a generic company which would eventually file an ANDA with aParagraph IV Certification for any of these listed patents.

Thus, by patenting a maximum number of possible solid forms, even if these are not further developed and used, innovator companies can more efficiently protect their own products. Such patents must obviously meet the same patentability criteria as other inventions. Conversely, a generic company can launch its own product if, after the basic molecule patent has expired, it discovers a new solid form, i.e. a form with no IP protection and suitable characteristics for product development.

In both cases, a very sensitive tool as SR-XRPD can play a key role in helping the detection and characterization of a maximum number of polymorphs.

 Accurate and direct characterization of the API polymorphic forms and detection of trace amounts has proven to be of paramount importance (e.g. Paxil^®, Cefdinir) whereas poorly conducted screens and unsuccessful patenting strategies, on the other hand, can have significant negative commercial consequences (e.g. Ritonavir).

Interestingly, in the US the first ANDA approved by FDA with paragraph IV certification is entitled to 180-days marketing exclusivity. Initially granted only when theANDA applicant having filed Paragraph IV Certification could prevail in the litigation with the originator, the new FDA guidance suppresses the “successul defence”requirement and the 180-days exclusivity is decided on a case-by-case basis and can therefore be granted even if the case is settled.

While there has been much discussion by policymakers and stakeholders about the effects of “secondary patents” on the pharmaceutical industry, there is no empirical evidence on their prevalence or determinants. Characterizing the landscape of secondary patents is important in light of recent court decisions in the U.S. that may make them more difficult to obtain, and for developing countries considering restrictions on secondary patents.

It is seen the claims of the 1304 Orange Book listed patents on all new molecular entities approved in the U.S. between 1988 and 2005, and coded the patents as including chemical compound claims (claims covering the active molecule itself) and/or one of several types of secondary claims. It is seen that  distinguish between patents with any secondary claims, and those with only secondary claims and no chemical compound claims (“independent” secondary patents).

It is seen  that secondary claims are common in the pharmaceutical industry. It is seen that independent secondary patents tend to be filed and issued later than chemical compound patents, and are also more likely to be filed after the drug is approved. When present, independent formulation patents add an average of 6.5 years of patent life (95% C.I.: 5.9 to 7.3 years), independent method of use patents add 7.4 years (95% C.I.: 6.4 to 8.4 years), and independent patents on polymorphs, isomers, prodrug, ester, and/or salt claims add 6.3 years (95% C.I.: 5.3 to 7.3 years). evidence that late-filed independent secondary patents are more common for higher sales drugs

Polymorph quantification. REF 79

SEE A SLIDESHARE PRESENTATION

http://www.slideshare.net/reychemist/polymorph-quant

The ability to detect and quantify polymorphism of pharmaceuticals is critically important in ensuring that the formulated product delivers the desired therapeutic properties because different polymorphic forms of a drug exhibit different solubilities, stabilities and bioavailabilities. The purpose of this study is to develop an effective method for quantitative analysis of a small amount of one polymorph within a binary polymorphic mixture. Sulfamerazine (SMZ), an antibacterial drug, was chosen as the model compound. The effectiveness and accuracy of powder X-ray diffraction (PXRD), Raman microscopy and differential scanning calorimetry (DSC) for the quantification of SMZ polymorphs were studied and compared.

Low heating rate in DSC allowed complete transformation from Form I to Form II to take place, resulting in a highly linear calibration curve. Our results showed that DSC and PXRD are capable in providing accurate measurement of polymorphic content in the SMZ binary mixtures while Raman is the least accurate technique for the system studied.

DSC provides a rapid and accurate method for offline quantification of SMZ polymorphs, and PXRD provides a non-destructive, non-contact analysis.A novel method of detecting very low levels of different polymorphs using high-resolution X-ray powder diffraction with a synchrotron light source has been developed by Zach-Zambon Chemicals of Italy. Key to the project has been development of software to enable appropriate data presentation.The issue of polymorphism in pharmaceuticals has attracted increasing attention over the past 20 years and is something to which development scientists and the regulatory authorities pay considerable attention.

http://www.scientificupdate.co.uk/blog/item/polymorph-detection-and-quantification-a-novel-method.html

REFERENCES

63……..POLYMORPHISM AND PATENTS http://www.collegio.unibo.it/uploads/ideas/joelbernstein.pdf 64…Aprepitant case study FTIR.. READING MATERIALhttp://alpha.chem.umb.edu/chemistry/ch361/spring%2005/ftir%20polymorph.pdf 65…..READ………….An Overview of Solid Form Screening During Drug Development, http://www.icdd.com/ppxrd/10/presentations/PPXRD-10_Ann_Newman.pdf 66…..CRYSTALLIZATION..http://www.intechopen.com/books/advanced-topics-on-crystal-growth/crystallization-from-the-conformer-to-the-crystal

67International Conference on Harmonization Q6A Guideline: Specifications for New Drug Substances and Products: Chemical Substances, October 1999.

68Center for Drug Evaluation and Research Guidance: Submitting Supporting Documentation in Drug Applications for the Manufacture of Drug Substances, February 1987.

69S. Byrn, R. Pfeiffer, M. Ganey, C. Hoiberg, and G. Poochikian. Pharmaceutical solids: A strategic approach to regulatory considerations. Pharm. Res. 12:945-954 (1995). 70

1. H. Brittain. Methods for the characterization of polymorphs and solvates. In H. G. Brittain (ed.) Polymorphism in Pharmaceutical Solids. Marcel Dekker, Inc., New York, 1999, pp. 227-278.
2. L. X. Yu and G. L. Amidon GL. Analytical Solutions to Mass Transfer. In: G. L. Amidon, P. I. Lee, and E. M. Topp (eds.) Transport Processes in Pharmaceutical Systems. Marcel Dekker, Inc., 1999, p. 23-54.
3. G. L. Amidon, H. Lennernas, V. P. Shah, and J. R. Crison. A theoretical basis for a biopharmaceutic drug classification: the correlation of in vitro drug product dissolution and in vivo bioavailability. Pharm. Res. 12:413-420 (1995).
4. L. X. Yu, G. L. Amidon, J. E. Polli, H. Zhao, M. Mehta, D. P. Conner, V. P. Shah, L. J. Lesko, M.-L. Chen, V. H. L. Lee, and A. S. Hussain. Biopharmaceutics Classification System: The scientific basis for biowaiver extension. Pharm. Res. 19:921-925 (2002).
5. S. R. Byrn, R. R. Pfeiffer, and J. G. Stowell. Solid-State Chemistry of Drugs. 2^nd Edition, SSCI, Inc., West Lafayette, Indiana, pp. 259-366.
6. H. G. Brittain and E. F. Fiese. Effect of pharmaceutical processing on drug polymorphs and solvates. In H. G. Brittain (ed.) Polymorphism in Pharmaceutical Solids. Marcel Dekker, Inc., New York, 1999, pp. 331-362.

71 CRYSTALS POLYMORPHS IN PHARMAhttp://www.fcfar.unesp.br/arquivos/475753.pdf

72 API………….POLYMORPHISM pharmaceutical ingredients (APIs).http://www.ncbi.nlm.nih.gov/pubmed/19275600

73 polymorphs and co-crystals – ICDD  POWER POINT PRESENTATION

74Thermodynamic stability and transformation of pharmaceutical … http://pac.iupac.org/publications/pac/pdf/2005/pdf/7703×0581.pdf

75http://www.imc.cas.cz/nmr/projekt/ws/springer.pdf

76  High-throughput crystallization: polymorphs, salts, co-crystalsand solvates of pharmaceutical solidshttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.85.5397&rep=rep1&type=pdf

77 Crystalline Solid – University of Utah College of Pharmacy Homepharmacy.utah.edu/pharmaceutics/pdf/Crystalline.pdf‎Form – a term encompassing all solids – polymorphs, solvates, amorphous … inPolymorphism in Pharmaceutical Solids

78..related to xrd

1. Bish, DL and Post, JE, editors. 1989. Modern Powder Diffraction. Reviews in Mineralogy, Vol. 20. Mineralogical Society of America
2. Cullity, B. D. 1978. Elements of X-ray diffraction. 2nd ed. Addison-Wesley, Reading, Mass
3. I. Ivanisevic, R. B. McClurg and P. J. Schields: Uses of X-Ray Powder Diffraction in the Pharmaceutical Industry, Pharmaceutical Sciences Encyclopedia: Drug Discovery, Development and Manufacturing, Ed. by Shayne C. Gad., p. 1-42 (2010).
4. S. R. Byrn, S. Bates and I. Ivanisevic: Regulatory Aspects of X-ray Powder Diffraction, Part 1, American Pharmaceutical Review, p.55-59 (2005)
5. D. Beckers: The power of X-ray analysis, Pharmaceutical Technology Europe (2010), p.29,30.
6. M. Sakata, S. Aoyagi, T. Ogura & E. Nishibori (2007): Advanced Structural Analyses by Third Generation Synchrotron Radiation Powder Diffraction, AIP Conference Proceedings, Vol. 879, pp. 1829-1832 (2007).
7. Bergamaschi, A.; Cervellino, A.; Dinapoli, R.; Gozzo, F.; Henrich, B.; Johnson, I.; Kraft, P.; Mozzanica, A.; Schmitt, B.; Shi, X.: The MYTHEN detector for X-ray powder diffraction experiments at the Swiss Light Source. J. Synchrotron Rad. 17 (2010) 653–668.
8. R.B. Von Dreele, P.W. Stephens, G.D. Smith, and R.H. Blessing: The First Protein Crystal Structure Determined from X-ray Powder Diffraction Data: a Variant of T3R3 Human Insulin Zinc Complex Produced by Grinding,Acta Cryst. D 56, 1549-53 (2000).
9. Margiolaki, I., Wright, J. P., Fitch, A. N., Fox, G. C. & Von Dreele, R. B.: Synchrotron X-ray powder diffraction study of hexagonal turkey egg-white lysozyme, Acta Cryst. D61, 423–432 (2005). See also: Margiolaki, I. & Wright, J. P.: Powder crystallography on macromolecules, Acta Cryst. A64, 169–180 (2008).
10. Fundamentals of Crystallography,C. Giacovazzo Ed., International Union of Crystallography, Oxford Science Publications, Third Edition (2011).
11. The basics of Crystallography and Diffraction (Third edition, 2010), Christopher Hammond, IUCr, Oxford Science Publications; ISBN 978-0-19-954645-9. See also: X-Ray Structure Determination, A practical Guide, George H. Stout and Lyle H. Jensen, Wiley Interscience.
12. Bruni G, Gozzo F, Capsoni D, Bini M, Macchi P, Simoncic P, Berbenni V., Milanese C., Girella A., Ferrari S. and Marini A., Thermal, Spectroscopic, and Ab Initio Structural Characterization of Carprofen Polymorphs, J. Pharm. Sciences 100(6), 2321 (2011).
13. Brunelli, M., Wright, J. P., Vaughan, G. B. M., Mora, A. J. & Fitch, A. N.: Solving Larger Molecular Crystal Structures from Powder Diffraction Data by Exploiting Anisotropic Thermal Expansion. Angew. Chem. (2003) 115, 2075–2078.
14. T. Wessels, Ch. Baerlocher and L.B. McCusker: Single-crystal-like diffraction data from polycrystalline materials, Science (1999), 284, 477-479.
15. Shankland, K., David, W. I. F., Csoka, T. & McBride, L.: Structure solution of Ibuprofen from powder diffraction data by the application of a genetic algorithm combined with prior conformational analysis,  Intl. J. Pharmaceut. (1998) 165, 117–126.
16. A. Altomare, C. Cuocci, C. Giacovazzo, A. Moliterni and R. Rizzi: The dual-space resolution bias correction algorithm: applications to powder data, J. Appl. Cryst. (2010). 43, 798-804.
17. G.Oszlanyi and A. Suto: The charge flipping algorithm, Acta Cryst. (2008). A64, 123–134 and references herein.
18. Boccaleri, E., Carniato, F., Croce, G., Viterbo, D., van Beek, W., Emerich H. and Milanesio, M.,In-situ simultaneous Raman/high-resolution X-ray powder diffraction study of transformations occurring in materials at non-ambient conditions, J. Appl. Cryst., 2007, 40, 684-693.
19. Scarlett N.V.Y. and Madsen I. C., Quantification of phases with partial or no known crystal structures, Powder Diffraction (2006) 21, 278-284
20. Giannini C., Guagliardi A. and Millini R., Quantitative phase analysis by combining the Rietveld and the whole-pattern decomposition methods, J. Appl. Cryst., 2002, 35, 481-490.
21. Scardi, P.; Leoni, M.: Line profile analysis: pattern modeling versus profile fitting, J. Appl. Cryst. 39 (2006) 24–31. Scardi, P.; Leoni, M.: Whole Powder Pattern Modelling, Acta Crystall. A58 (2002) 190–200
22. Local structure from total scattering and atomic pair distribution function (PDF) analysis, In Powder diffraction: theory and practice, (Royal Society of Chemistry, London England, 2008), Robert E. Dinnebier and Simon J. L. Billinge, Eds., pp. 464 – 493.
23. Neder R. B. And Korsunskiy V. I., Structure of nanoparticles from powder diffraction data using the pair distribution function, 2005 J. Phys.: Condens. Matter 17 S125
24. A. Cervellino, C. Giannini, A. Guagliardi, Determination of nanoparticle, size distribution and lattice parameter from x-ray data for monoatomic materials with f.c.c. cubic unit cell, J. Appl. Cryst. 36, 1148-1158 (2003).
25. P.W. Stephens, D.E. Cox, and A.N. Fitch, Synchrotron Radiation Powder Diffraction in Structure Determination by Powder Diffraction, pp. 49-87, edited by W.I.F. David, K. Shankland, L.B. McCusker, and C. Baerlocher, (Oxford University Press, 2002)
26. Joel Bernstein: Polymorphism in Molecular Crystals, IUCr Monographs on Crystallography (2002), Oxford Science Publications.
27. Polymorphism in Pharmaceutical Solids, Ed. By Harry G. Brittain, Drugs and The Pharmaceutical Sciences, Vol. 192
28. Tremayne, M.: The impact of powder diffraction on the structural study of organic materials., Philosophical Transactions of the Royal Society of London Series A: Chemistry and Life Sciences Triennial Issue, 362: 2691 (2004).
29. Law D, Schmitt EA, Marsh KC, Everitt EA,Wang W, Fort JJ, Krill SL, Qiu Y. Ritonavir-PEG 8000 amorphous solid dispersions: in vitro and in vivo evaluations. J. Pharm. Sci. 2004; 93 (3): 563–567.
30. Bruni G., Berbenni V., Milanese C., Girella A., Cardini A., Lanfranconi S. and Marini A.,Determination of the nateglinide polymorphic purity through DSC, J. Pharm. and Biomed. Anal. 54 (2011) 1196-1199.
31. Aaltonen J., Alleso M., Mirza S., Koradia V., Gordon K.C and Rantanen J., Solid form screening – A review. European Journal of Pharmaceutics and Biopharmaceutics 71 (2009), 23-37.
32. Srivastava D., The Food and Drug Administration and Patent Law at a Crossroads: The Listing of Polymorph Patents as a Barrier to Generic Drug Entry. Food and Drug Law Journal, Vol. 59, No.2 (2004), 339-354.
33. Grabowski H. G., Kyle M., Mortimer R., Long G. & Kirson N., Evolving Brand-name And Generic Drug Competition May Warrant A Revision Of The Hatch-Waxman Act. Health Affairs, 30, no.11 (2011):2157-2166.
34. Rakowski W. A and Mazzochi D. M., The case of disappearing polymorph: ‘Inherent anticipation’ and the impact of Smithkline Beecham Corp. v Apotex Corp. (Paxil®) on patent validity and infringement by inevitable conversion’. Journal of Generic Medicine, Vol.1, No.2 (2006):131-139.
35. Cabri W., Ghetti P., Pozzi G. and Alpegiani M., Polymorphisms and Patent, Market, and Legal Battles: Cefdinir Case Study. Organic Process Research & Development 2007, 11, 64-72.
36. Bauer J, Spanton S, Henry R, Quick J, Dziki W, Porter W, Morris J., Ritonavir: an extraordinary example of conformational polymorphism, Pharm Res. 2001 Jun;18(6):859-66.

79………..related to estimation

1. McCrone, W.C. in Physics and Chemistry of the Organic Solid State, Vol. 2, (Eds.: D. Fox, M.M. Labes, A. Weissberger), Interscience, New York, 1965, pp. 725-767.
2. Bernstein, J., Davey, R.L., and Henck, JO, Concomitant Polymorphism, Angew.Chem.Int. Ed. 1999,38, 3440-3461.
3. Polymorphism in Pharmaceutical Solids, Second Edition (Drugs and the Pharmaceutical Sciences) Harry G. Brittain (Editor) Informa HealthCare; 2nd edition (July 27, 2009)
4. Otsuka, M., Kato, F. and Matsuda, Y., Determination of indomethacin polymorphic contents by chemometric near-infrared spectroscopy and conventional powder X-ray diffractometry, Analyst, 2001, 126, 1578 – 1582.
5. Patel, A.D., Luner, P. E. and Kemper, M. S., Low-level Determination of Polymorph composition in Physical Mixtures by Near-Infrared Reflectance Spectroscopy, J Pharm Sci 2001, 90, 360-370.
6. Agatonovic-Kustrin S, Wu V, Rades, T, Saville, D, Tucker, I G, Powder diffractometric assay of two polymorphic forms of ranitidine hydrochloride Int J Pharm 1999, 184, 107.
7. Hurst, V.J., Schroeder, P.A., and Styron, R.W. Accurate quantification of quartz and other phases by powder X-ray diffractometry. Analytica Chimica. Acta, 1997, 337, 233-252
8. Campbell Roberts, S.N., Williams A.C., Grimsey, I.M., and Booth S.W., Quantitative analysis of mannitol polymorphs. X-ray powder diffractometry—exploring preferred orientation effects J. Pharm. Biomed. Anal., 2002, 28, 1149-1159.

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FONDAPARINUX

Fondaparinux is a drug belonging to the group of the antithrombotic agents and are used to prevent deep vein thrombosis in patients undergoing orthopedic surgery. It is also used for the treatment of severe venous thrombosis and pulmonary

фондапаринукс (fondaparinux) | EMA:Link, US FDA:link

114870-03-0  ………..10x SODIUM SALT

GSK-576428  Org-31540  SR-90107SR-90107A  

launched 2002

Arixtra, Quixidar, Fondaparinux sodium, Fondaparin sodium, Arixtra (TN), Fondaparinux, Org-31540, AC1LCS4W, SR-90107A

Fondaparinux (Arixtra) is a synthetic pentasaccharide anticoagulant. Apart from the O-methyl group at the reducing end of the molecule, the identity and sequence of the five monomeric sugar units contained in fondaparinux is identical to a sequence of five monomeric sugar units that can be isolated after either chemical or enzymatic cleavage of the polymeric glycosaminoglycan heparin and heparan sulfate (HS). This monomeric sequence in heparin and HS is thought to form the high affinity binding site for the natural anti-coagulant factor, antithrombin III (ATIII).

Binding of heparin/HS to ATIII has been shown to increase the anti-coagulant activity of antithrombin III 1000-fold. Fondaparinux potentiates the neutralizing action ofATIII on activated Factor X 300-fold. Fondaparinux may be used: to prevent venous thromboembolism in patients who have undergone orthopedic surgery of the lower limbs (e.g. hip fracture, hip replacement and knee surgery); to prevent VTE in patients undergoing abdominal surgery who are are at high risk of thromboembolic complications; in the treatment of deep vein thrombosis (DVT) and pumonary embolism (PE); in the management of unstable angina (UA) and non-ST segment elevation myocardial infarction (NSTEMI); and in the management of ST segment elevation myocardial infarction (STEMI).

FONDAPARINUX

Fondaparinux (trade name Arixtra) is an anticoagulant medication chemically related to low molecular weight heparins. It is marketed byGlaxoSmithKline. A generic version developed by Alchemia is marketed within the US by Dr. Reddy’s Laboratories.

Fondaparinux is a synthetic pentasaccharide Factor Xa inhibitor. Apart from the O-methyl group at the reducing end of the molecule, the identity and sequence of the five monomeric sugar units contained in fondaparinux is identical to a sequence of five monomeric sugar units that can be isolated after either chemical or enzymatic cleavage of the polymeric glycosaminoglycans heparin and heparan sulfate (HS). Within heparin and heparan sulfate this monomeric sequence is thought to form the high affinity binding site for the anti-coagulant factor antithrombin III (ATIII). Binding of heparin/HS to ATIII has been shown to increase the anti-coagulant activity of antithrombin III 1000 fold. In contrast to heparin, fondaparinux does not inhibit thrombin.

Fondaparinux is given subcutaneously daily. Clinically, it is used for the prevention of deep vein thrombosis in patients who have had orthopedic surgery as well as for the treatment of deep vein thrombosis and pulmonary embolism.

One potential advantage of fondaparinux over LMWH or unfractionated heparin is that the risk for heparin-induced thrombocytopenia (HIT) is substantially lower. Furthermore, there have been case reports of fondaparinux being used to anticoagulate patients with established HIT as it has no affinity to PF-4. However, its renal excretion precludes its use in patients with renal dysfunction.

Unlike direct factor Xa inhibitors, it mediates its effects indirectly through antithrombin III, but unlike heparin, it is selective for factor Xa.^[1]

Fondaparinux is similar to enoxaparin in reducing the risk of ischemic events at nine days, but it substantially reduces major bleeding and improves long term mortality and morbidity.^[2]

It has been investigated for use in conjunction with streptokinase.^[3]

Fondaparinux sodium, a selective coagulation factor Xa inhibitor, was first launched in the U.S. in 2002 by GlaxoSmithKline in a subcutaneous injection formulation for the prophylaxis of deep venous thrombosis (DVT) which may lead to pulmonary embolism in patients at risk for thromboembolic complications who are undergoing hip replacement, knee replacement, hip fracture surgery or abdominal surgery. The product is available in Japan for the treatment of acute deep venous thrombosis and acute pulmonary thromboembolism. In 2004, GlaxoSmithKline launched fondaparinux as an injection to be used in conjunction with warfarin sodium for the subcutaneous treatment of acute pulmonary embolism and DVT.

In 2007, GlaxoSmithKline received approval in the E.U. for the treatment of acute coronary syndrome (ACS), specifically unstable angina or non-ST segment elevation myocardial infarction (UA/NSTEMI) and ST-segment elevation myocardial infarction (STEMI), while in the U.S. an approvable letter was received for this indication. Currently, the drug is in clinical development at GlaxoSmithKline for the treatment of venous limb superficial thrombosis.

Fondaparinux Molecule

GlaxoSmithKline had filed a regulatory application in the E.U. seeking approval of fondaparinux sodium for the prevention of venous thromboembolic events (VTE), however; in 2008, the application was withdrawn for commercial reasons. Commercial launch in Japan for the product for the prevention of venous thromboembolism in high risk patients undergoing surgery in the abdomen took place in 2008.

In 2010, the EMA approved a regulatory application filed by GlaxoSmithKline seeking approval of a once-daily formulation of fondaparinux sodium for the treatment of adults with acute symptomatic spontaneous superficial-vein thrombosis (SVT) of the lower limbs without concomitant DVT. Product launch took place in the U.K. for this indication the same year.

The antithrombotic activity of fondaparinux is the result of antithrombin III (ATIII)-mediated selective inhibition of Factor Xa. By selectively binding to ATIII, the drug potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII. Neutralization of Factor Xa, in turn, interrupts the blood coagulation cascade and thus inhibits thrombin formation and thrombus development. Fondaparinux does not inactivate thrombin (activated Factor II) and has no known effect on platelet function. At the recommended dose, no effects have been demonstrated on fibrinolytic activity or bleeding time.

Originally developed by Organon and Sanofi (formerly known as sanofi-aventis), fondaparinux sodium is currently available in approximately 30 countries. In 2004, Organon transferred its rights to the drug to Sanofi in exchange for revenues based on future sales from jointly developed antithrombotic products and in early 2005, GlaxoSmithKline also acquired the antithrombotic.

At the beginning of 2005, GlaxoSmithKline signed a two-year agreement with Adolor (acquired by Cubist in 2011) for the copromotion of fondaparinux sodium in the U.S. In Sepetember 2013, Aspen Pharmacare acquired Arixtra global rights (excluding China, India and Pakistan) from GlaxoSmithKline for the treatment of thrombosis with GlaxoSmithKline commercializing the product in Indonesia under licence from Aspen.

Chemical structure

Abbreviations

• GlcNS6S = 2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside
• GlcA = β-D-glucopyranuronoside
• GlcNS3,6S = 2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl
• IdoA2S = 2-O-sulfo-α-L-idopyranuronoside
• GlcNS6SOMe = methyl-O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside

The sequence of monosaccharides is D-GlcNS6S-α-(1,4)-D-GlcA-β-(1,4)-D-GlcNS3,6S-α-(1,4)-L-IdoA2S-α-(1,4)-D-GlcNS6S-OMe, as shown in the following structure:

ARIXTRA (fondaparinux sodium) Injection is a sterile solution containing fondaparinux sodium. It is a synthetic and specific inhibitor of activatedFactor X (Xa). Fondaparinux sodium is methyl O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-β-D-glucopyranuronosyl-( 1→4)-O-2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-2-Osulfo-α-L-idopyranuronosyl-(1→4)-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside, decasodium salt.

The molecular formula of fondaparinux sodium is C₃₁H₄₃N₃Na₁₀O₄₉S₈ and its molecular weight is 1728. The structural formula is provided below:

ARIXTRA is supplied as a sterile, preservative-free injectable solution for subcutaneous use.

Each single-dose, prefilled syringe of ARIXTRA, affixed with an automatic needle protection system, contains 2.5 mg of fondaparinux sodium in 0.5 mL, 5.0 mg of fondaparinux sodium in 0.4 mL, 7.5 mg of fondaparinux sodium in 0.6 mL, or 10.0 mg of fondaparinux sodium in 0.8 mL of an isotonic solutionof sodium chloride and water for injection. The final drug product is a clear and colorless to slightly yellow liquid with a pH between 5.0 and 8.0.

……………….

INTRODUCTION

In U.S. Patent No. 7,468,358, Fondaparinux sodium is described as the “only anticoagulant thought to be completely free of risk from HIT-2 induction.” The biochemical and pharmacologic rationale for the development of a heparin pentasaccharide in Thromb. Res., 86(1), 1-36, 1997 by Walenga et al. cited the recently approved synthetic pentasaccharide Factor Xa inhibitor Fondaparinux sodium. Fondaparinux has also been described in Walenga et al., Expert Opin. Investig. Drugs, Vol. 11, 397-407, 2002 and Bauer, Best Practice & Research Clinical Hematology, Vol. 17, No. 1, 89-104, 2004.

Fondaparinux sodium is a linear octasulfated pentasaccharide (oligosaccharide with five monosaccharide units ) molecule having five sulfate esters on oxygen (O-sulfated moieties) and three sulfates on a nitrogen (N- sulfated moieties). In addition, Fondaparinux contains five hydroxyl groups in the molecule that are not sulfated and two sodium carboxylates. Out of five saccharides, there are three glucosamine derivatives and one glucuronic and one L-iduronic acid. The five saccharides are connected to each other in alternate α and β glycosylated linkages (see Figure 1).

Figure 1 Fondaparinux Sodium

Monosaccharide E Monosaccharide D Monosaccharide C Monosaccharide B Monosaccharide A derived from derived from derived from derived from derived from

Monomer E Monomer D Monomer C Monomer B1 Monomer A2

Fondaparinux Sodium

Fondaparinux sodium is a chemically synthesized methoxy derivative of the natural pentasaccharide sequence, which is the active site of heparin that mediates the interaction with antithrombin (Casu et al., J. Biochem., 197, 59, 1981). It has a challenging pattern of O- and N- sulfates, specific glycosidic stereochemistry, and repeating units of glucosamines and uronic acids (Petitou et al, Progress in the Chemistry of Organic Natural Product, 60, 144-209, 1992).

The monosaccharide units comprising the Fondaparinux molecule are labeled as per the convention in Figure 1, with the glucosamine unit on the right referred to as monosaccharide A and the next, an uronic acid unit to its left as B and subsequent units, C, D and E respectively. The chemical synthesis of Fondaparinux starts with monosaccharides of defined structures that are themselves referred to as Monomers A2, Bl, C, D and E, for differentiation and convenience, and they become the corresponding monosaccharides in fondaparinux sodium.

Due to this complex mixture of free and sulfated hydroxyl groups, and the presence of N- sulfated moieties, the design of a synthetic route to Fondaparinux requires a careful strategy of protection and de-protection of reactive functional groups during synthesis of the molecule. Previously described syntheses of Fondaparinux all adopted a similar strategy to complete the synthesis of this molecule. This strategy can be envisioned as having four stages.

The strategy in the first stage requires selective de-protection of five out of ten hydroxyl groups. During the second stage these five hydroxyls are selectively sulfonated. The third stage of the process involves the de -protection of the remaining five hydroxyl groups. The fourth stage of the process is the selective sulfonation of the 3 amino groups, in the presence of five hydroxyl groups that are not sulfated in the final molecule. This strategy can be envisioned from the following fully protected pentasaccharide, also referred to as the late-stage intermediate.

In this strategy, all of the hydroxyl groups that are to be sulfated are protected with an acyl protective group, for example, as acetates (R = CH₃) or benzoates (R = aryl) (Stages 1 and 2) All of the hydroxyl groups that are to remain as such are protected with benzyl group as benzyl ethers (Stage 3). The amino group, which is subsequently sulfonated, is masked as an azide (N₃) moiety (Stage 4). R¹ and R² are typically sodium in the active pharmaceutical compound (e.g., Fondaparinux sodium).

This strategy allows the final product to be prepared by following the synthetic operations as outlined below: a) Treatment of the late- stage intermediate with base to hydrolyze (deprotect) the acyl ester groups to reveal the five hydroxyl groups. The two R¹ and R² ester groups are hydrolyzed in this step as well.

b) Sulfonation of the newly revealed hydroxyl groups.

c) Hydrogenation of the O-sulfated pentasaccharide to de-benzylate the five benzyl- protected hydroxyls, and at the same time, unmask the three azides to the corresponding amino groups.

d) On the last step of the operation, the amino groups are sulfated selectively at a high pH, in the presence of the five free hydroxyls to give Fondaparinux (Figure 1). While the above strategy has been shown to be viable, it is not without major drawbacks. One drawback lies in the procedure leading to the fully protected pentasaccharide (late stage intermediate), especially during the coupling of the D-glucuronic acid to the next adjacent glucose ring (the D-monomer to C-monomer in the EDCBA nomenclature shown in Figure 1). Sugar oligomers or oligosaccharides, such as Fondaparinux, are assembled using coupling reactions, also known as glycosylation reactions, to “link” sugar monomers together. The difficulty of this linking step arises because of the required stereochemical relationship between the D-sugar and the C-sugar, as shown below:

The stereochemical arrangement illustrated above in Figure 2 is described as having a β- configuration at the anomeric carbon of the D-sugar (denoted by the arrow). The linkage between the D and C units in Fondaparinux has this specific stereochemistry. There are, however, competing β- and α-glycosylation reactions.

The difficulties of the glycosylation reaction in the synthesis of Fondaparinux is well known. In 1991 Sanofi reported a preparation of a disaccharide intermediate in 51% yield having a 12/1 ratio of β/α stereochemistry at the anomeric position (Duchaussoy et al., Bioorg. & Med. Chem. Lett., 1(2), 99-102, 1991).

In another publication (Sinay et al, Carbohydrate Research, 132, C5-C9, 1984) yields on the order of 50% with coupling times on the order of 6- days are reported. U.S. Patent No. 4,818,816 {see e.g., column 31, lines 50-56) discloses a 50% yield for the β-glycosylation.

Alchemia’s U.S. Patent No. 7,541,445 is even less specific as to the details of the synthesis of this late-stage Fondaparinux synthetic intermediate. The ’445 Patent discloses several strategies for the assembly of the pentasaccharide (1+4, 3+2 or 2+3) using a 2-acylated D-sugar (specifically 2-allyloxycarbonyl) for the glycosylation coupling reactions. However, Alchemia’s strategy involves late-stage pentasaccharides that all incorporate a 2-benzylated D- sugar.

The transformation of acyl to benzyl is performed either under acidic or basic conditions. Furthermore, these transformations, using benzyl bromide or benzyl trichloroacetimidate, typically result in extensive decomposition and the procedure suffers from poor yields. Thus, such transformations (at a disaccharide, trisaccharide, and pentasaccharide level) are typically not acceptable for industrial scale production.

Examples of fully protected pentasaccharides are described in Duchaussoy et al, Bioorg. Med. Chem. Lett., 1 (2), 99-102, 1991; Petitou et al, Carbohydr. Res., 167, 67-75, 1987; Sinay et al, Carbohydr. Res., 132, C5-C9, 1984; Petitou et al., Carbohydr. Res., 1147, 221-236, 1986; Lei et al., Bioorg. Med. Chem., 6, 1337-1346, 1998; Ichikawa et al., Tet. Lett., 27(5), 611-614, 1986; Kovensky et al, Bioorg. Med. Chem., 1999, 7, 1567-1580, 1999.

These fully protected pentasaccharides may be converted to the O- and N-sulfated pentasaccharides using the four steps (described earlier) of: a) saponification with LiOHZH₂CVNaOH, b) O-sulfation by an Et₃N- SO₃ complex; c) de-benzylation and azide reduction via H₂/Pd hydrogenation; and d) N-sulfation with a pyridine-SO₃ complex.

Even though many diverse analogs of the fully protected pentasaccharide have been prepared, none use any protective group at the 2-position of the D unit other than a benzyl group. Furthermore, none of the fully protected pentasaccharide analogs offer a practical, scaleable and economical method for re-introduction of the benzyl moiety at the 2-position of the D unit after removal of any participating group that promotes β-glycosylation.

Furthermore, the coupling of benzyl protected sugars proves to be a sluggish, low yielding and problematic process, typically resulting in substantial decomposition of the pentasaccharide (prepared over 50 synthetic steps), thus making it unsuitable for a large [kilogram] scale production process.

Ref. 1. Sinay et al, Carbohydr. Res., 132, C5-C9, 1984.

Ref. 2. Petitou et al., Carbohydr. Res., 147, 221-236. 1986

It has been a general strategy for carbohydrate chemists to use base-labile ester-protecting group at 2-position of the D unit to build an efficient and stereoselective β-glycosidic linkage. To construct the β-linkage carbohydrate chemists have previously acetate and benzoate ester groups, as described, for example, in the review by Poletti et al., Eur. J. Chem., 2999-3024, 2003.

The ester group at the 2-position of D needs to be differentiated from the acetate and benzoates at other positions in the pentasaccharide. These ester groups are hydrolyzed and sulfated later in the process and, unlike these ester groups, the 2-hydroxyl group of the D unit needs to remain as the hydroxyl group in the final product, Fondaparinux sodium.

Some of the current ester choices for the synthetic chemists in the field include methyl chloro acetyl and chloro methyl acetate [MCA or CMA] . The mild procedures for the selective removal of theses groups in the presence of acetates and benzoates makes them ideal candidates. However, MCA/CMA groups have been shown to produce unwanted and serious side products during the glycosylation and therefore have not been favored in the synthesis of Fondaparinux sodium and its analogs. For by-product formation observed in acetate derivatives see Seeberger et al., J. Org. Chem., 2004, 69, 4081-93.

Similar by-product formation is also observed using chloroacetate derivatives. See Orgueira et al., Eur. J. Chem., 9(1), 140-169, 2003.

The levulinyl group can be rapidly and almost quantitatively removed by treatment with hydrazine hydrate as the deprotection reagent as illustrated in the example below. Under the same reaction conditions primary and secondary acetate and benzoate esters are hardly affected by hydrazine hydrate. See, e.g., Seeberger et al, J. Org. Chem., 69, 4081-4093, 2004.

The syntheses of Fondaparinux sodium described herein takes advantage of the levulinyl group in efficient construction of the trisaccharide EDC with improved β- selectivity for the coupling under milder conditions and increased yields.

Substitution of the benzyl protecting group with a THP moiety provides its enhanced ability to be incorporated quantitatively in position-2 of the unit D of the pentasaccharide. Also, the THP group behaves in a similar manner to a benzyl ether in terms of function and stability. In the processes described herein, the THP group is incorporated at the 2-position of the D unit at this late stage of the synthesis (i.e., after the D and C units have been coupled through a 1,2-trans glycosidic (β-) linkage). The THP protective group typically does not promote an efficient β- glycosylation and therefore is preferably incorporated in the molecule after the construction of the β-linkage.

Fondaparinux and sodium salt thereof can be prepared from pure compound of Formula II by following the teachings from Bioorganic and Medicinal Chemistry Letters, 1(2), p. 95-98 (1991). A second aspect of the present invention provides a process for the preparation of 4-0- -D-glucopyranosyl-l,6-anhydro- -D-glucopyranose, represented by STR BELOW

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SYNTHESIS

EP2464668A2   AND US8288515

The scheme below exemplifies some of the processes of the present invention disclosed herein.

The tetrahydropyranyl (THP) protective group and the benzyl ether protective group are suitable hydroxyl protective groups and can survive the last four synthetic steps (described above) in the synthesis of Fondaparinux sodium, even under harsh reaction conditions. Certain other protecting groups do not survive the last four synthetic steps in high yield.

Synthesis of Fondaparinux

Fondaparinux was prepared using the following procedure:

Synthesis of Fondaparinux

Fondaparinux was prepared using the following procedure:

The ester moieties in EDCBA Pentamer were hydrolyzed with sodium and lithium hydroxide in the presence of hydrogen peroxide in dioxane mixing at room temperature for 16 hours to give the pentasaccharide intermediate API1. The five hydroxyl moieties in API1 were sulfated using a pyridine-sulfur trioxide complex in dimethylformamide, mixing at 60° C. for 2 hours and then purified using column chromatography (CG-161), to give the pentasulfated pentasaccharide API2. The intermediate API2 was then hydrogenated to reduce the three azides on sugars E, C and A to amines and the reductive deprotection of the five benzyl ethers to their corresponding hydroxyl groups to form the intermediate API3. This transformation occurs by reacting API2 with 10% palladium/carbon catalyst with hydrogen gas for 72 hours. The three amines on API3 were then sulfated using the pyridine-sulfur trioxide complex in sodium hydroxide and ammonium acetate, allowing the reaction to proceed for 12 hours. The acidic work-up procedure of the reaction removes the THP group to provide crude fondaparinux which is purified and is subsequently converted to its salt form. The crude mixture was purified using an ion-exchange chromatographic column (HiQ resin) followed by desalting using a size exclusion resin or gel filtration (Biorad Sephadex G25) to give the final API, fondaparinux sodium

Experimental Procedures Preparation of IntD1 Bromination of Glucose Pentaacetate

To a 500 ml flask was added 50 g of glucose pentaacetate (C₆H₂₂O₁₁) and 80 ml of methylene chloride. The mixture was stirred at ice-water bath for 20 min HBr in HOAc (33%, 50 ml) was added to the reaction mixture. After stirring for 2.5 hr another 5 ml of HBr was added to the mixture. After another 30 min, the mixture was added 600 ml of methylene chloride. The organic mixture was washed with cold water (200 ml×2), Saturated NaHCO₃(200 ml×2), water (200 ml) and brine (200 ml×2). The organic layer was dried over Na₂SO₄ and the mixture was evaporated at RT to give white solid as final product, bromide derivative, IntD1 (˜95% yield). C₁₄H₁₉BrO₉, TLC R_f=0.49, SiO₂, 40% ethyl acetate/60% hexanes; Exact Mass 410.02.

Preparation of IntD2 by Reductive Cyclization

To a stirring mixture of bromide IntD1 (105 g), tetrabutylammonium iodide (60 g, 162 mmol) and activated 3 Å molecular sieves in anhydrous acetonitrile (2 L), solid NaBH₄ (30 g, 793 mmol) was added. The reaction was heated at 40° C. overnight. The mixture was then diluted with dichloromethane (2 L) and filtered through Celite®. After evaporation, the residue was dissolved in 500 ml ethyl acetate. The white solid (Bu₄NI or Bu₄NBr) was filtered. The ethyl acetate solution was evaporated and purified by chromatography on silica gel using ethyl acetate and hexane as eluent to give the acetal-triacetate IntD2 (˜60-70% yield). TLC R_f=0.36, SiO₂ in 40% ethyl acetate/60% hexanes.

Preparation of IntD3 by De-Acetylation

To a 1000 ml flask was added triacetate IntD2 (55 g) and 500 ml of methanol. After stirring 30 min, the reagent NaOMe (2.7 g, 0.3 eq) was added and the reaction was stirred overnight. Additional NaOMe (0.9 g) was added to the reaction mixture and heated to 50° C. for 3 hr. The mixture was neutralized with Dowex 50Wx8 cation resin, filtered and evaporated. The residue was purified by silica gel column to give 24 g of trihydroxy-acetal IntD3. TLC R_f=0.36 in SiO₂, 10% methanol/90% ethyl acetate.

Preparation of IntD4 by Benzylidene Formation

To a 1000 ml flask was added trihydroxy compound IntD3 (76 g) and benzaldehyde dimethyl acetate (73 g, 1.3 eq). The mixture was stirred for 10 min, after which D(+)-camphorsulfonic acid (8.5 g, CSA) was added. The mixture was heated at 50° C. for two hours. The reaction mixture was then transferred to separatory funnel containing ethyl acetate (1.8 L) and sodium bicarbonate solution (600 ml). After separation, the organic layer was washed with a second sodium bicarbonate solution (300 ml) and brine (800 ml). The two sodium carbonate solutions were combined and extracted with ethyl acetate (600 ml×2). The organic mixture was evaporated and purified by silica gel column to give the benzylidene product IntD4 (77 g, 71% yield). TLC R_f=0.47, SiO₂ in 40% ethyl acetate/60% hexanes.

Preparation of IntD5 by Benzylation

To a 500 ml flask was added benzylidene acetal compound IntD4 (21 g,) in 70 ml THF. To another flask (1000 ml) was added NaH (2 eq). The solution of IntD4 was then transferred to the NaH solution at 0° C. The reaction mixture was stirred for 30 min, then benzyl bromide (16.1 ml, 1.9 eq) in 30 ml THF was added. After stirring for 30 min, DMF (90 ml) was added to the reaction mixture. Excess NaH was neutralized by careful addition of acetic acid (8 ml). The mixture was evaporated and purified by silica gel column to give the benzyl derivative IntD5. (23 g) TLC R_f=0.69, SiO₂ in 40% ethyl acetate/60% hexanes.

Preparation of IntD6 by Deprotection of Benzylidene

To a 500 ml flask was added the benzylidene-acetal compound IntD5 (20 g) and 250 ml of dichloromethane, the reaction mixture was cooled to 0° C. using an ice-water-salt bath. Aqueous TFA (80%, 34 ml) was added to the mixture and stirred over night. The mixture was evaporated and purified by silica gel column to give the dihydroxy derivative IntD6. (8 g, 52%). TLC R_f=0.79, SiO₂ in 10% methanol/90% ethyl acetate.

Preparation of IntD7 by Oxidation of 6-Hydroxyl

To a 5 L flask was added dihydroxy compound IntD6 (60 g), TEMPO (1.08 g), sodium bromide (4.2 g), tetrabutylammonium chloride (5.35 g), saturated NaHCO₃ (794 ml) and EtOAc (1338 ml). The mixture was stirred over an ice-water bath for 30 min To another flask was added a solution of NaOCl (677 ml), saturated NaHCO₃ (485 ml) and brine (794 ml). The second mixture was added slowly to the first mixture (over about two hrs). The resulting mixture was then stirred overnight. The mixture was separated, and the inorganic layer was extracted with EtOAc (800 ml×2). The combined organic layers were washed with brine (800 ml). Evaporation of the organic layer gave 64 g crude carboxylic acid product IntD7 which was used in the next step use without purification. TLC R_f=0.04, SiO₂ in 10% methanol/90% ethyl acetate.

Preparation of Monomer D by Benzylation of the Carboxylic Acid

To a solution of carboxylic acid derivative IntD7 (64 g) in 600 ml of dichloromethane, was added benzyl alcohol (30 g) and N-hydroxybenzotriazole (80 g, HOBt). After stirring for 10 min triethylamine (60.2 g) was added slowly. After stirring another 10 min, dicyclohexylcarbodiimide, (60.8 g, DCC) was added slowly and the mixture was stirred overnight. The reaction mixture was filtered and the solvent was removed under reduced pressure followed by chromatography on silica gel to provide 60.8 g (75%, over two steps) of product, Monomer D. TLC R_f=0.51, SiO₂ in 40% ethyl acetate/60% hexanes.

Synthesis of the BA Dimer

Step 1. Preparation of BMod1, Levulination of Monomer B1

A 100 L reactor was charged with 7.207 Kg of Monomer B1 (21.3 moles, 1 equiv), 20 L of dry tetrahydrofuran (THF) and agitated to dissolve. When clear, it was purged with nitrogen and 260 g of dimethylamino pyridine (DMAP, 2.13 moles, 0.1 equiv) and 11.05 L of diisopropylethylamine (DIPEA, 8.275 kg, 63.9 moles, 3 equiv) was charged into the reactor. The reactor was chilled to 10-15° C. and 13.7 kg levulinic anhydride (63.9 mol, 3 equiv) was transferred into the reactor. When the addition was complete, the reaction was warmed to ambient temperature and stirred overnight or 12-16 hours. Completeness of the reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. When the reaction was complete, 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. The mixture was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L of water, 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight. The yield of the isolated syrup of BMod1 was 100%.

Synthesis of the BA Dimer

Step 2. Preparation of BMod2, TFA Hydrolysis of BMod1

A 100 L reactor was charged with 9296 Kg of 4-Lev Monomer B1 (BMod1) (21.3 mol, 1 equiv). The reactor chiller was turned to <5° C. and stirring was begun, after which 17.6 L of 90% TFA solution (TFA, 213 mole, 10 equiv) was transferred into the reactor. When the addition was complete, the reaction was monitored by TLC and HPLC. The reaction took approximately 2-3 hours to reach completion. When the reaction was complete, the reactor was chilled and 26.72 L of triethylamine (TEA, 19.4 Kg, 191.7 mole, 0.9 equiv) was transferred into the reactor. An additional 20 L of water and 20 L ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer was extracted (EtOAc layer) with 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 50:50, 80:20 (EtOAc/heptane), 100% EtOAc, 5:95, 10:90 (MeOH/EtOAc). The pure fractions were pooled and evaporated to a syrup. The yield of the isolated syrup, BMod2 was 90%.

Synthesis of the BA Dimer

Step 3. Preparation of BMod3, Silylation of BMod2

A 100 L reactor was charged with 6.755 Kg 4-Lev-1,2-DiOH Monomer B1 (BMod2) (17.04 mol, 1 equiv), 2328 g of imidazole (34.2 mol, 2 equiv) and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., then 5.22 L tert-butyldiphenylchloro-silane (TBDPS-Cl, 5.607 Kg, 20.4 mol, 1.2 equiv) was transferred into the reactor. When addition was complete, the chiller was turned off and the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (40% ethyl acetate/hexane) and HPLC. The reaction took approximately 3 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. Dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The yield of BMod3 was about 80%.

Synthesis of the BA Dimer

Step 4. Preparation of BMod4, Benzoylation

A 100 L reactor was charged with 8.113 Kg of 4-Lev-1-Si-2-OH Monomer B1 (BMod3) (12.78 mol, 1 equiv), 9 L of pyridine and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., after which 1.78 L of benzoyl chloride (2155 g, 15.34 mol, 1.2 equiv) was transferred into the reactor. When addition was complete, the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (40% ethyl acetate/heptane) and HPLC. The reaction took approximately 3 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The DCM solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). Isolated syrup BMod4 was obtained in 91% yield.

Synthesis of the BA Dimer

Step 5. Preparation of BMod5, Desilylation

A 100 L reactor was charged with 8.601 Kg of 4-Lev-1-Si-2-Bz Monomer B1 (BMod4) (11.64 mol, 1 equiv) in 30 L terahydrofuran. The reactor was purged with nitrogen and chilled to 0° C., after which 5.49 Kg of tetrabutylammonium fluoride (TBAF, 17.4 mol, 1.5 equiv) and 996 mL (1045 g, 17.4 mol, 1.5 equiv) of glacial acetic acid were transferred into the reactor. When the addition was complete, the reaction was stirred at ambient temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. The reaction took approximately 6 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min, after which the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20 (EtOAc/heptane) and 200 L 100% EtOAc. Pure fractions were pooled and evaporated to a syrup. The intermediate BMod5 was isolated as a syrup in 91% yield.

Synthesis of the BA Dimer

Step 6: Preparation of BMod6, TCA Formation

A 100 L reactor was charged with 5.238 Kg of 4-Lev-1-OH-2-Bz Monomer B1 (BMod5) (10.44 mol, 1 equiv) in 30 L of DCM. The reactor was purged with nitrogen and chilled to 10-15° C., after which 780 mL of diazabicyclo undecene (DBU, 795 g, 5.22 mol, 0.5 equiv) and 10.47 L of trichloroacetonitrile (TCA, 15.08 Kg, 104.4 mol, 10 equiv) were transferred into the reactor. Stirring was continued and the reaction was kept under a nitrogen atmosphere. After reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by HPLC and TLC (40:60 ethyl acetate/heptane). The reaction took approximately 2 hours to reach completion. When the reaction was complete, 20 L of water and 10 L of dichloromethane were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was separated with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/Heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of BMod6 was 73%.

Synthesis of the BA Dimer

Step 7. Preparation of AMod1, Acetylation of Monomer A2

A 100 L reactor was charged with 6.772 Kg of Monomer A2 (17.04 mole, 1 eq.), 32.2 L (34.8 Kg, 340.8 moles, 20 eq.) of acetic anhydride and 32 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C. When the temperature reached −20° C., 3.24 L (3.63 Kg, 25.68 mol, 1.5 equiv) of boron trifluoride etherate (BF₃.Et₂O) was transferred into the reactor. After complete addition of boron trifluoride etherate, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 3-5 hours for completion. When the reaction was complete, extraction was performed with 3×15 L of 10% sodium bicarbonate and 20 L of water. The organic phase (DCM) was evaporated to a syrup (bath temp. 40° C.) and allowed to dry overnight. The syrup was purified in a 200 L silica column using 140 L each of the following gradient profiles: 5:95, 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of AMod1 was 83%.

Synthesis of the BA Dimer

Step 8. Preparation of AMod3,1-Methylation of AMod1

A 100 L reactor was charged with 5891 g of acetyl Monomer A2 (AMod1) (13.98 mole, 1 eq.) in 32 L of dichloromethane. The reactor was purged with nitrogen and was chilled to 0° C., after which 2598 mL of trimethylsilyl iodide (TMSI, 3636 g, 18 mol, 1.3 equiv) was transferred into the reactor. When addition was complete, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 2-4 hours to reach completion. When the reaction was complete, the mixture was diluted with 20 L of toluene. The solution was evaporated to a syrup and was co-evaporated with 3×6 L of toluene. The reactor was charged with 36 L of dichloromethane (DCM), 3.2 Kg of dry 4 Å Molecular Sieves, 15505 g (42 mol, 3 equiv) of tetrabutyl ammonium iodide (TBAI) and 9 L of dry methanol. This was stirred until the TBAI was completely dissolved, after which 3630 mL of diisopropyl-ethylamine (DIPEA, 2712 g, 21 moles, 1.5 equiv) was transferred into the reactor in one portion. The completion of the reaction was monitored by HPLC and TLC (30:70 ethyl acetate/heptane). The reaction took approximately 16 hours for completion. When the reaction was complete, the molecular sieves were removed by filtration. Added were 20 L EtOAc and extracted with 4×20 L of 25% sodium thiosulfate and 20 L 10% NaCl solutions. The organic layer was separated and dried with 8-12 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 5:95, 10:90, 20:80, 30:70 and 40:60 (EtOAc/heptane). The pure fractions were pooled and evaporated to give intermediate AMod3 as a syrup. The isolated yield was 75%.

Synthesis of the BA Dimer

Step 9. Preparation of AMod4, DeAcetylation of AMod3

A 100 L reactor was charged with 4128 g of 1-Methyl 4,6-Diacetyl Monomer A2 (AMod3) (10.5 mol, 1 equiv) and 18 L of dry methanol and dissolved, after which 113.4 g (2.1 mol, 0.2 equiv) of sodium methoxide was transferred into the reactor. The reaction was stirred at room temperature and monitored by TLC (40% ethyl acetate/hexane) and HPLC. The reaction took approximately 2-4 hours for completion. When the reaction was complete, Dowex 50Wx8 cation resin was added in small portions until the pH reached 6-8. The Dowex 50Wx8 resin was filtered and the solution was evaporated to a syrup (bath temp. 40° C.). The syrup was diluted with 10 L of ethyl acetate and extracted with 20 L brine and 20 L water. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight at the same temperature. The isolated yield of the syrup AMod4 was about 88%.

Synthesis of the BA Dimer

Step 10. Preparation of AMod5,6-Benzoylation

A 100 L reactor was charged with 2858 g of Methyl 4,6-diOH Monomer A2 (AMod4) (9.24 mol, 1 equiv) and co-evaporated with 3×10 L of pyridine. When evaporation was complete, 15 L of dichloromethane, 6 L of pyridine were transferred into the reactor and dissolved. The reactor was purged with nitrogen and chilled to −40° C. The reactor was charged with 1044 mL (1299 g, 9.24 mol, 1 equiv) of benzoyl chloride. When the addition was complete, the reaction was allowed to warm to −10° C. over a period of 2 hours. The reaction was monitored by TLC (60% ethyl acetate/hexane). When the reaction was completed, the solution was evaporated to a syrup (bath temp. 40° C.). This was co-evaporated with 3×15 L of toluene. The syrup was diluted with 40 L ethyl acetate. Extraction was carried out with 20 L of water and 20 L of brine solution. The Ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 5:95, 10:90, 20:80, 25:70 and 30:60 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup. The isolated yield of the intermediate AMod5 was 84%.

Synthesis of the BA Dimer

Step 11. Preparation of BA1, Coupling of Amod5 with BMod6

A 100 L reactor was charged with 3054 g of methyl 4-Hydroxy-Monomer A2 (AMod5) from Step 10 (7.38 mol, 1 equiv) and 4764 g of 4-Lev-1-TCA-Monomer B1 (BMod6) from Step 6 (7.38 mol, 1 equiv). The combined monomers were dissolved in 20 L of toluene and co-evaporated at 40° C. Co evaporation was repeated with an additional 2×20 L of toluene, after which 30 L of dichloromethane (DCM) was transferred into the reactor and dissolved. The reactor was purged with nitrogen and was chilled to below −20° C. When the temperature was between −20° C. and −40° C., 1572 g (1404 mL, 11.12 moles, 1.5 equiv) of boron trifluoride etherate (BF₃.Et₂O) were transferred into the reactor. After complete addition of boron trifluoride etherate, the reaction was allowed to warm to 0° C. and stirring was continued. The completeness of the reaction was monitored by HPLC and TLC (40:70 ethyl acetate/heptane). The reaction required 3-4 hours to reach completion. When the reaction was complete, 926 mL (672 g, 6.64 mol, 0.9 equiv) of triethylamine (TEA) was transferred into the mixture and stirred for an additional 30 minutes, after which 20 L of water and 10 L of dichloromethane were transferred into the reactor. The solution was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was separated with 2×20 L water and 20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. The dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and used in the next step. The isolated yield of the disaccharide BA1 was about 72%.

Synthesis of the BA Dimer

Step 12, Removal of Levulinate Methyl [(methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate)-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl]-2-deoxy-α-D-glucopyranoside

A 100 L reactor was charged with 4.104 Kg of 4-Lev BA Dimer (BA1) (4.56 mol, 1 equiv) in 20 L of THF. The reactor was purged with nitrogen and chilled to −20 to −25° C., after which 896 mL of hydrazine hydrate (923 g, 18.24 mol, 4 equiv) was transferred into the reactor. Stirring was continued and the reaction was monitored by TLC (40% ethyl acetate/heptane) and HPLC. The reaction took approximately 2-3 hour for the completion, after which 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (ETOAc layer) was extracted with 20 L 25% brine solutions. The ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). The pure fractions were pooled and evaporated to dryness. The isolated yield of the BA Dimer was 82%. Formula: C₄₂H₄₃N₃O₁₃; Mol. Wt. 797.80.

Synthesis of the EDC Trimer

Step 1. Preparation of EMod1, Acetylation

A 100 L reactor was charged with 16533 g of Monomer E (45 mole, 1 eq.), 21.25 L acetic anhydride (225 mole, 5 eq.) and 60 L of dichloromethane. The reactor was purged with nitrogen and was chilled to −10° C. When the temperature was at −10° C., 1.14 L (1277 g) of boron trifluoride etherate (BF₃.Et₂O, 9.0 moles, 0.2 eq) were transferred into the reactor. After the complete addition of boron trifluoride etherate, the reaction was allowed to warm to room temperature. The completeness of the reaction was monitored by TLC (30:70 ethyl acetate/heptane) and HPLC. The reaction took approximately 3-6 hours to reach completion. When the reaction was completed, the mixture was extracted with 3×50 L of 10% sodium bicarbonate and SOL of water. The organic phase (DCM) was evaporated to a syrup (bath temp. 40° C.) and allowed to dry overnight. The isolated yield of EMod1 was 97%.

Synthesis of the EDC Trimer

Step 2. Preparation of EMod2, De-Acetylation of Azidoglucose

A 100 L reactor was charged with 21016 g of 1,6-Diacetyl Monomer E (EMod1) (45 mole, 1 eq.), 5434 g of hydrazine acetate (NH₂NH₂.HOAc, 24.75 mole, 0.55 eq.) and 50 L of DMF (dimethyl formamide). The solution was stirred at room temperature and the reaction was monitored by TLC (30% ethyl acetate/hexane) and HPLC. The reaction took approximately 2-4 hours for completion. When the reaction was completed, 50 L of dichloromethane and 40 L of water were transferred into the reactor. This was stirred for 30 minutes and the layers were separated. This was extracted with an additional 40 L of water and the organic phase was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.) and dried overnight at the same temperature. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of intermediate EMod2 was 100%.

Synthesis of the EDC Trimer

Step 3. Preparation of EMod3, Formation of 1-TCA

A 100 L reactor was charged with 12752 g of 1-Hydroxy Monomer E (EMod2) (30 mole, 1 eq.) in 40 L of dichloromethane. The reactor was purged with nitrogen and stirring was started, after which 2.25 L of DBU (15 moles, 0.5 eq.) and 15.13 L of trichloroacetonitrile (150.9 moles, 5.03 eq) were transferred into the reactor. Stirring was continued and the reaction was kept under nitrogen. After the reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (30:70 ethyl acetate/Heptane) and HPLC. The reaction took approximately 2-3 hours to reach completion. When the reaction was complete, 40 L of water and 20 L of DCM were charged into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 40 L water and the DCM solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90 (DCM/EtOAc/heptane), 20:5:75 (DCM/EtOAc/heptane) and 20:10:70 DCM/EtOAc/heptane). Pure fractions were pooled and evaporated to give Intermediate EMod3 as a syrup. Isolated yield was 53%.

Synthesis of the EDC Trimer

Step 4. Preparation of ED Dimer, Coupling of E-TCA with Monomer D

A 100 L reactor was charged with 10471 g of 6-Acetyl-1-TCA Monomer E (EMod3) (18.3 mole, 1 eq., FW: 571.8) and 6594 g of Monomer D (16.47 mole, 0.9 eq, FW: 400.4). The combined monomers were dissolved in 20 L toluene and co-evaporated at 40° C. This was repeated with co-evaporation with an additional 2×20 L of toluene, after which 60 L of dichloromethane (DCM) were transferred into the reactor and dissolved. The reactor was purged with nitrogen and was chilled to −40° C. When the temperature was between −30° C. and −40° C., 2423 g (2071 mL, 9.17 moles, 0.5 eq) of TES Triflate were transferred into the reactor. After complete addition of TES Triflate the reaction was allowed to warm and stirring was continued. The completeness of the reaction was monitored by HPLC and TLC (35:65 ethyl acetate/Heptane). The reaction required 2-3 hours to reach completion. When the reaction was completed, 2040 mL of triethylamine (TEA, 1481 g, 0.8 eq.) were transferred into the reactor and stirred for an additional 30 minutes. The organic layer (DCM layer) was extracted with 2×20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 15:85, 20:80, 25:75, 30:70 and 35:65 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The ED Dimer was obtained in 81% isolated yield.

Synthesis of the EDC Trimer

Step 5. Preparation of ED1 TFA, Hydrolysis of ED Dimer

A 100 L reactor was charged with 7.5 Kg of ED Dimer (9.26 mol, 1 equiv). The reactor was chilled to <5° C. and 30.66 L of 90% TFA solution (TFA, 370.4 mol, 40 equiv) were transferred into the reactor. When the addition was completed the reaction was allowed to warm to room temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexanes) and HPLC. The reaction took approximately 3-4 hours to reach completion. When the reaction was completed, was chilled and 51.6 L of triethylamine (TEA, 37.5 Kg, 370.4 mole) were transferred into the reactor, after which 20 L of water & 20 L ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. Ethyl acetate solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 20:80, 30:70, 40:60, 50:50, 60:40 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup. Isolated yield of ED1 was about 70%.

Synthesis of the EDC Trimer

Step 6. Preparation of ED2, Silylation of ED1

A 100 L reactor was charged with 11000 g of 1,2-diOH ED Dimer (ED1) (14.03 mol, 1 equiv), 1910.5 g of imidazole (28.06 mol, 2 equiv) and 30 L of dichloromethane. The reactor was purged with nitrogen and chilled to −20° C., after which 3.53 L butyldiphenylchloro-silane (TBDPS-Cl, 4.628 Kg, 16.835 mol, 1.2 equiv) was charged into the reactor. When the addition was complete, the chiller was turned off and the reaction was allowed to warm to ambient temperature. The reaction was monitored by TLC (50% ethyl acetate/hexane) and HPLC. The reaction required 4-6 hours to reach completion. When the reaction was completed, 20 L of water and 10 L of dichloromethane were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. Dichloromethane solution was dried in 4-6 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). Intermediate ED2 was obtained in 75% isolated yield.

Synthesis of the EDC Trimer

Step 7. Preparation of ED3, D-Levulination

A 100 L reactor was charged with 19800 g of 1-Silyl ED Dimer (ED2) (19.37 moles, 1 equiv) and 40 L of dry tetrahydrofuran (THF) and agitated to dissolve. The reactor was purged with nitrogen and 237 g of dimethylaminopyridine (DMAP, 1.937 moles, 0.1 equiv) and 10.05 L of diisopropylethylamine (DIPEA, 63.9 moles, 3 equiv) were transferred into the reactor. The reactor was chilled to 10-15° C. and kept under a nitrogen atmosphere, after which 12.46 Kg of levulinic anhydride (58.11 moles, 3 eq) was charged into the reactor. When the addition was complete, the reaction was warmed to ambient temperature and stirred overnight or 12-16 hours. The completeness of the reaction was monitored by TLC (40:60 ethyl acetate/hexane) and by HPLC. 20 L of 10% citric acid, 10 L of water and 25 L of ethyl acetate were transferred into the reactor. This was stirred for 30 min and the layers were separated. The organic layer (EtOAc layer) was extracted with 20 L of water, 20 L 5% sodium bicarbonate and 20 L 25% brine solutions. The ethyl acetate solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The ED3 yield was 95%.

Synthesis of the EDC Trimer

Step 8. Preparation of ED4, Desilylation of ED3

A 100 L reactor was charged with 19720 g of 1-Silyl-2-Lev ED Dimer (ED3) (17.6 mol, 1 equiv) in 40 L of THF. The reactor was chilled to 0° C., after which 6903 g of tetrabutylammonium fluoride trihydrate (TBAF, 26.4 mol, 1.5 equiv) and 1511 mL (26.4 mol, 1.5 equiv) of glacial acetic acid were transferred into the reactor. When the addition was complete, the reaction was stirred and allowed to warm to ambient temperature. The reaction was monitored by TLC (40:60 ethyl acetate/hexane) and HPLC. The reaction required 3 hours to reach completion. When the reaction was completed, 20 L of water and 10 L of dichloromethane were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified using a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20 (EtOAc/heptane) and 200 L 100% EtOAc. The pure fractions were pooled and evaporated to a syrup and used in the next step. The isolated yield of ED4 was about 92%.

Synthesis of the EDC Trimer

Step 9. Preparation of ED5, TCA Formation

A 100 L reactor was charged with 14420 g of 1-OH-2-Lev ED Dimer (ED4) (16.35 mol, 1 equiv) in 30 L of dichloromethane. The reactor was purged with nitrogen and stirring was begun, after which 1222 mL of diazabicycloundecene (DBU, 8.175 mol, 0.5 equiv) and 23.61 Kg of trichloroacetonitrile (TCA, 163.5 mol, 10 equiv) were transferred into the reactor. Stirring was continued and the reaction was kept under nitrogen. After reagent addition, the reaction was allowed to warm to ambient temperature. The reaction was monitored by HPLC and TLC (40:60 ethyl acetate/heptane). The reaction took approximately 2 hours for reaction completion. When the reaction was completed, 20 L of water and 10 L of DCM were transferred into the reactor and stirred for 30 min and the layers were separated. The organic layer (DCM layer) was extracted with 20 L water and 20 L 25% brine solutions. The dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The solution was evaporated to a syrup (bath temp. 40° C.). The crude product was purified using a 200 L silica column using 140-200 L each of the following gradient profiles: 10:90, 20:80, 30:70, 40:60 and 50:50 (EtOAc/heptane). The pure fractions were pooled and evaporated to a syrup and used in the next step. The isolated yield of intermediate ED5 was about 70%.

Synthesis of the EDC Trimer

Step 10.

Preparation of EDC Trimer, Coupling of ED5 with Monomer C 6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-α-D-glucopyranosyl-(1→4)-benzyl (3-O-benzyl-2-O-levulinoyl)-β-D-glucopyranosyluronate-(1→4)-(3-O-acetyl-1,6-anhydro-2-azido)-2-deoxy-β-D-glucopyranose

A 100 L reactor was charged with 12780 g of 2-Lev 1-TCA ED Dimer (ED5) (7.38 mole, 1 eq., FW) and 4764 g of Monomer C (7.38 mole, 1 eq). The combined monomers were dissolved in 20 L toluene and co-evaporated at 40° C. Repeated was co-evaporation with an additional 2×20 L of toluene, after which 60 L of dichloromethane (DCM) was transferred into the reactor and dissolved. The reactor was purged with nitrogen and chilled to −20° C. When the temperature was between −20 and −10° C., 2962 g (11.2 moles, 0.9 eq) of TES Triflate were transferred into the reactor. After complete addition of TES Triflate the reaction was allowed to warm to 5° C. and stirring was continued. Completeness of the reaction was monitored by HPLC and TLC (35:65 ethyl acetate/Heptane). The reaction required 2-3 hours to reach completion. When the reaction was completed, 1133 g of triethylamine (TEA, 0.9 eq.) were transferred into the reactor and stirred for an additional 30 minutes. The organic layer (DCM layer) was extracted with 2×20 L 25% 4:1 sodium chloride/sodium bicarbonate solution. Dichloromethane solution was dried in 6-8 Kg of anhydrous sodium sulfate. The syrup was purified in a 200 L silica column using 140-200 L each of the following gradient profiles: 15:85, 20:80, 25:75, 30:70 and 35:65 (EtOAc/heptane). Pure fractions were pooled and evaporated to a syrup. The isolated yield of EDC Trimer was 48%. Formula: C₅₅H₆₀N₆O₁₈; Mol. Wt. 1093.09. The ¹H NMR spectrum (d6-acetone) of the EDC trimer is shown in FIG. 3.

Preparation of EDC1

Step 1:

Anhydro Ring Opening & Acetylation 6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-1,3,6-tri-O-acetyl-β-D-glucopyranose

7.0 Kg (6.44 mol) of EDC Trimer was dissolved in 18 L anhydrous Dichloromethane. 6.57 Kg (64.4 mol, 10 eq) of Acetic anhydride was added. The solution was cooled to −45 to −35° C. and 1.82 Kg (12.9 mol, 2 eq) of Boron Trifluoride etherate was added slowly. Upon completion of addition, the mixture was warmed to 0-10° C. and kept at this temperature for 3 hours until reaction was complete by TLC and HPLC. The reaction was cooled to −20° C. and cautiously quenched and extracted with saturated solution of sodium bicarbonate (3×20 L) while maintaining the mixture temperature below 5° C. The organic layer was extracted with brine (1×20 L), dried over anhydrous sodium sulfate, and concentrated under vacuum to a syrup. The resulting syrup of EDC1 (6.74 Kg) was used for step 2 without further purification. The ¹H NMR spectrum (d6-acetone) of the EDC-1 trimer is shown in FIG. 4.

Preparation of EDC2

Step 2:

Deacetylation 6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-β-D-glucopyranose

The crude EDC1 product obtained from step 1 was dissolved in 27 L of Tetrahydrofuran and chilled to 15-20° C., after which 6 Kg (55.8 mol) of benzylamine was added slowly while maintaining the reaction temperature below 25° C. The reaction mixture was stirred for 5-6 hours at 10-15° C. Upon completion, the mixture was diluted with ethyl acetate and extracted and quenched with 10% citric acid solution (2×20 L) while maintaining the temperature below 25° C. The organic layer was extracted with 10% NaCl/1% sodium bicarbonate (1×20 L). The extraction was repeated with water (1×10 L), dried over anhydrous sodium sulfate and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel yielded 4.21 Kg (57% yield over 2 steps) of EDC2[ also referred to as 1-Hydroxy-6-Acetyl EDC Trimer]. The ¹H NMR spectrum (d6-acetone) of the EDC-2 trimer is shown in FIG. 5.

Preparation of EDC3

Step 3:

Formation of TCA Derivative 6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-1-O-trichloroacetimidoyl-β-D-glucopyranose

4.54 Kg (3.94 mol) of EDC2 was dissolved in 20 L of Dichloromethane. 11.4 Kg (78.8 mol, 20 eq) of Trichloroacetonitrile was added. The solution was cooled to −15 to −20° C. and 300 g (1.97 mol, 0.5 eq) of Diazabicycloundecene was added. The reaction was allowed to warm to 0-10° C. and stirred for 2 hours or until reaction was complete. Upon completion, water (20 L) was added and the reaction was extracted with an additional 10 L of DCM. The organic layer was extracted with brine (1×20 L), dried over anhydrous sodium sulfate, and concentrated under vacuum to a syrup. Column chromatographic separation using silica gel and 20-60% ethyl acetate/heptane gradient yielded 3.67 Kg (72% yield) of 1-TCA derivative, EDC3. The ¹H NMR spectrum (d6-acetone) of the EDC-3 trimer is shown in FIG. 6.

Preparation of EDCBA1

Step 4:

Coupling of EDC3 with BA Dimer Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl)-(1→4)-O-[benzyl 3-O-benzyl-2-O-levulinoyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside

3.67 Kg (2.83 mol) of EDC3 and 3.16 Kg (3.96 mol, 1.4 eq) of BA Dimer was dissolved in 7-10 L of Toluene and evaporated to dryness. The resulting syrup was coevaporated with Toluene (2×15 L) to remove water. The dried syrup was dissolved in 20 L of anhydrous Dichloromethane, transferred to the reaction flask, and cooled to −15 to −20° C. 898 g (3.4 mol, 1.2 eq) of triethylsilyl triflate was added while maintaining the temperature below −5° C. When the addition was complete, the reaction was immediately warmed to −5 to 0° C. and stirred for 3 hours. The reaction was quenched by slowly adding 344 g (3.4 mol, 1.2 eq) of Triethylamine. Water (15 L) was added and the reaction was extracted with an additional 10 L of DCM. The organic layer was extracted with a 25% 4:1 Sodium Chloride/Sodium Bicarbonate solution (2×20 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. The resulting syrup of the pentasaccharide, EDCBA1 was used for step 5 without further purification. The ¹H NMR spectrum (d6-acetone) of the EDCBA-1 pentamer is shown in FIG. 7.

Preparation of EDCBA2

Step 5:

Hydrolysis of Levulinyl moiety Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl)-(1→4)—O-[benzyl 3-O-benzyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl)-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside

The crude EDCBA1 from step 4 was dissolved in 15 L of Tetrahydrofuran and chilled to −20 to −25° C. A solution containing 679 g (13.6 mol) of Hydrazine monohydrate and 171 g (1.94 mol) of Hydrazine Acetate in 7 L of Methanol was added slowly while maintaining the temperature below −20° C. When the addition was complete, the reaction mixture was allowed to warm to 0-10° C. and stirred for several hours until the reaction is complete, after which 20 L of Ethyl acetate was added and the reaction was extracted with 10% citric acid (2×12 L). The organic layer was washed with water (1×12 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel and 10-45% ethyl acetate/heptane gradient yielded 2.47 Kg (47.5% yield over 2 steps) of EDCBA2. The ¹H NMR spectrum (d6-acetone) of the EDCBA-2 pentamer is shown in FIG. 8.

Preparation of EDCBA Pentamer

Step 6:

THP Formation Methyl O-6-O-acetyl-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-[benzyl 3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronate]-(1→4)-O-2-azido-2-deoxy-3,6-di-O-acetyl-α-D-glucopyranosyl-(1→4)-O-[methyl 2-O-benzoyl-3-O-benzyl-α-L-Idopyranosyluronate]-(1→4)-2-azido-6-O-benzoyl-3-O-benzyl-2-deoxy-α-D-glucopyranoside

2.47 Kg (1.35 mol) of EDCBA2 was dissolved in 23 L Dichloroethane and chilled to 10-15° C., after which 1.13 Kg (13.5 mol, 10 eq) of Dihydropyran and 31.3 g (0.135 mol, 0.1 eq) of Camphorsulfonic acid were added. The reaction was allowed warm to 20-25° C. and stirred for 4-6 hours until reaction was complete. Water (15 L) was added and the reaction was extracted with an additional 10 L of DCE. The organic layer was extracted with a 25% 4:1 Sodium Chloride/Sodium Bicarbonate solution (2×20 L), dried over anhydrous sodium sulfate, and evaporated under vacuum to a syrup. Column chromatographic separation using silica gel and 10-35% ethyl acetate/heptane gradient yielded 2.28 Kg (88.5% yield) of fully protected EDCBA Pentamer. The ¹H NMR spectrum (d6-acetone) of the EDCBA pentamer is shown in FIG. 9.

Preparation of API1

Step 1:

Saponification Methyl O-2-azido-2-deoxy-3,4-di-O-benzyl-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-azido-2-deoxy-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-α-L-Idopyranosyluronosyl-(1→4)-2-azido-3-O-benzyl-2-deoxy-α-D-glucopyranoside disodium salt

To a solution of 2.28 Kg (1.19 mol) of EDCBA Pentamer in 27 L of Dioxane and 41 L of Tetrahydrofuran was added 45.5 L of 0.7 M (31.88 mol, 27 eq) Lithium hydroxide solution followed by 5.33 L of 30% Hydrogen peroxide. The reaction mixture was stirred for 10-20 hours to remove the acetyl groups. Then, 10 L of 4 N (40 mol, 34 eq) sodium hydroxide solution was added. The reaction was allowed to stir for an additional 24-48 hours to hydrolyze the benzyl and methyl esters completely. The reaction was then extracted with ethyl acetate. The organic layer was extracted with brine solution and dried with anhydrous sodium sulfate. Evaporation of the solvent under vacuum gave a syrup of API1 [also referred to as EDCBA(OH)₅] which was used for the next step without further purification.

Preparation of API2

Step 2:

O-Sulfonation Methyl O-2-azido-2-deoxy-3,4-di-O-benzyl-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-azido-2-deoxy-3,6-di-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-benzyl-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-azido-2-deoxy-6-O-sulfo-α-D-glucopyranoside, heptasodium salt

The crude product of API1 [aka EDCBA(OH)₅] obtained in step 1 was dissolved in 10 L Dimethylformamide. To this was added a previously prepared solution containing 10.5 Kg (66 moles) of sulfur trioxide-pyridine complex in 10 L of Pyridine and 25 L of Dimethylformamide. The reaction mixture was heated to 50° C. over a period of 45 min. After stiffing at 1.5 hours at 50° C., the reaction was cooled to 20° C. and was quenched into 60 L of 8% sodium bicarbonate solution that was kept at 10° C. The pH of the quench mixture was maintained at pH 7-9 by addition of sodium bicarbonate solution. When all the reaction mixture has been transferred, the quench mixture was stirred for an additional 2 hours and pH was maintained at pH 7 or greater. When the pH of quench has stabilized, it was diluted with water and the resulting mixture was purified using a preparative HPLC column packed with Amberchrom CG161-M and eluted with 90%-10% Sodium Bicarbonate (5%) solution/Methanol over 180 min. The pure fractions were concentrated under vacuum and was then desalted using a size exclusion resin or gel filtration (Biorad) G25 to give 1581 g (65.5% yield over 2 steps) of API2 [also referred to as EDCBA(OSO₃)₅]. The ¹H NMR spectrum (d6-acetone) of API-2 pentamer is shown in FIG. 10.

Preparation of API3

Step 3:

Hydrogenation Methyl O-2-amino-2-deoxy-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2-O-tetrahydropyranyl-β-D-glucopyranosyluronosyl-(1→4)-O-2-amino-2-deoxy-3,6-di-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-amino-2-deoxy-6-O-sulfo-α-D-glucopyranoside, heptasodium salt

A solution of 1581 g (0.78 mol) of O-Sulfated pentasaccharide API2 in 38 L of Methanol and 32 L of water was treated with 30 wt % of Palladium in Activated carbon under 100 psi of Hydrogen pressure at 60-65° C. for 60 hours or until completion of reaction. The mixture was then filtered through 1.0μ and 0.2μ filter cartridges and the solvent evaporated under vacuum to give 942 g (80% yield) of API3 [also referred to as EDCBA(OSO₃)₅(NH₂)₃]. The ¹H NMR spectrum (d6-acetone) of API-3 pentamer is shown in FIG. 11.

Preparation of Fondaparinux Sodium

Step 4:

N-Sulfation & Removal of THP Methyl O-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)—O-β-D-glucopyranuronosyl-(1→4)-O-2-deoxy-3,6-di-O-sulfo-2-(sulfoamino)-α-D-glucopyranosyl-(1→4)-O-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-2-deoxy-6-O-sulfo-2-(sulfoamino)-α-D-glucopyranoside, decasodium salt

To a solution of 942 g (0.63 mol) of API3 in 46 L of water was slowly added 3.25 Kg (20.4 mol, 32 eq) of Sulfur trioxide-pyridine complex, maintaining the pH of the reaction mixture at pH 9-9.5 during the addition using 2 N sodium hydroxide solution. The reaction was allowed to stir for 4-6 hours at pH 9.0-9.5. When reaction was complete, the pH was adjusted to pH 7.0 using 50 mM solution of Ammonium acetate at pH 3.5. The resulting N-sulfated EDCBA(OSO₃)₅(NHSO₃)₃ mixture was purified using Ion-Exchange Chromatographic Column (Varian Preparative 15 cm HiQ Column) followed by desalting using a size exclusion resin or gel filtration (Biorad G25). The resulting mixture was then treated with activated charcoal and the purification by ion-exchange and desalting were repeated to give 516 g (47.6% yield) of the purified Fondaparinux Sodium form.

Analysis of the Fondaparinux sodium identified the presence of P1, P2, P3, and P4 in the fondaparinux. P1, P2, P3, and P4 were identified by standard analytical methods.

INTERMEDIATES

The monomers used in the processes described herein may be prepared as described in the art, or can be prepared using the methods described herein.

The synthesis of Monomer A-2 (CAS Registry Number 134221-42-4) has been described in the following references: Arndt et al., Organic Letters, 5(22), 4179-4182, 2003; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; and Sakairi et al., Journal of the Chemical Society, Chemical Communications, (5), 289-90, 1991, and the references cited therein, which are hereby incorporated by reference in their entireties.

Monomer C(CAS Registry Number 87326-68-9) can be synthesized using the methods described in the following references: Ganguli et al., Tetrahedron: Asymmetry, 16(2), 411-424, 2005; Izumi et al., Journal of Organic Chemistry, 62(4), 992-998, 1997; Van Boeckel et al., Recueil: Journal of the Royal Netherlands Chemical Society, 102(9), 415-16, 1983; Wessel et al.,Helvetica Chimica Acta, 72(6), 1268-77, 1989; Petitou et al., U.S. Pat. No. 4,818,816 and references cited therein, which are hereby incorporated by reference in their entireties.

Monomer E (CAS Registry Number 55682-48-9) can be synthesized using the methods described in the following literature references: Hawley et al., European Journal of Organic Chemistry, (12), 1925-1936, 2002; Dondoni et al., Journal of Organic Chemistry, 67(13), 4475-4486, 2002; Van der Klein et al., Tetrahedron, 48(22), 4649-58, 1992; Hori et al., Journal of Organic Chemistry, 54(6), 1346-53, 1989; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; Tailler et al.,Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry, (23), 3163-4, (1972-1999) (1992); Paulsen et al., Chemische Berichte, 111(6), 2334-47, 1978; Dasgupta et al., Synthesis, (8), 626-8, 1988; Paulsen et al., Angewandte Chemie, 87(15), 547-8, 1975; and references cited therein, which are hereby incorporated by reference in their entireties.

Monomer B-1 (CAS Registry Number 444118-44-9) can be synthesized using the methods described in the following literature references: Lohman et al., Journal of Organic Chemistry, 68(19), 7559-7561, 2003; Orgueira et al., Chemistry—A European Journal, 9(1), 140-169, 2003; Manabe et al., Journal of the American Chemical Society, 128(33), 10666-10667, 2006; Orgueira et al., Angewandte Chemie, International Edition, 41(12), 2128-2131, 2002; and references cited therein, which are hereby incorporated by reference in their entireties.
Synthesis of Monomer D
Monomer D was prepared in 8 synthetic steps from glucose pentaacetate using the following procedure:

Pentaacetate SM-B was brominated at the anomeric carbon using HBr in acetic acid to give bromide derivative IntD1. This step was carried out using the reactants SM-B, 33% hydrogen bromide, acetic acid and dichloromethane, stirring in an ice water bath for about 3 hours and evaporating at room temperature. IntD1 was reductively cyclized with sodium borohydride and tetrabutylammonium iodide in acetonitrile using 3 Å molecular sieves as dehydrating agent and stirring at 40° C. for 16 hours to give the acetal derivative, IntD2. The three acetyl groups in IntD2 were hydrolyzed by heating with sodium methoxide in methanol at 50° C. for 3 hours and the reaction mixture was neutralized using Dowex 50WX8-100 resin (Aldrich) in the acid form to give the trihydroxy acetal derivative IntD3.

The C4 and C6 hydroxyls of IntD3 were protected by mixing with benzaldehyde dimethyl acetate and camphor sulphonic acid at 50° C. for 2 hours to give the benzylidene-acetal derivative IntD4. The free hydroxyl at the C3 position of IntD4 was deprotonated with sodium hydride in THF as solvent at 0° C. and alkylated with benzyl bromide in THF, and allowing the reaction mixture to warm to room temperature with stirring to give the benzyl ether IntD5. The benzylidene moiety of IntD5 was deprotected by adding trifluoroacetic acid in dichloromethane at 0° C. and allowing it to warm to room temperature for 16 hours to give IntD6 with a primary hydroxyl group. IntD6 was then oxidized with TEMPO (2,2,6,6-tetramethyl-1-piperidine-N-oxide) in the presence of tetrabutylammonium chloride, sodium bromide, ethyl acetate, sodium chlorate and sodium bicarbonate, with stirring at room temperature for 16 hours to form the carboxylic acid derivative IntD7. The acid IntD7 was esterified with benzyl alcohol and dicyclohexylcarbodiimide (other reactants being hydroxybenzotriazole and triethylamine) with stirring at room temperature for 16 hours to give Monomer D.

Synthesis of the BA Dimer

The BA Dimer was prepared in 12 synthetic steps from Monomer B1 and Monomer A2 using the following procedure:

The C4-hydroxyl of Monomer B-1 was levulinated using levulinic anhydride and diisopropylethylamine (DIPEA) with mixing at room temperature for 16 hours to give the levulinate ester BMod1, which was followed by hydrolysis of the acetonide with 90% trifluoroacetic acid and mixing at room temperature for 4 hours to give the diol BMod2. The C1 hydroxyl of the diol BMod2 was silylated with tert-butyldiphenylsilylchloride by mixing at room temperature for 3 hours to give silyl derivative BMod3. The C2-hydroxyl was then benzoylated with benzoyl chloride in pyridine, and mixed at room temperature for 3 hours to give compound BMod4. The silyl group on BMod4 was then deprotected with tert-butyl ammonium fluoride and mixing at room temperature for 3 hours to give the C1-hydroyl BMod5. The C1-hydroxyl is then allowed to react with trichloroacetonitrile in the presence of diazobicycloundecane (DBU) and mixing at room temperature for 2 hours to give the trichloroacetamidate (TCA) derivative BMod6, which suitable for coupling, for example with Monomer A-2.

Monomer A-2 was prepared for coupling by opening the anhydro moiety with BF₃.Et₂O followed by acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1.

Monomer A2 was prepared for the coupling reaction by opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1. This transformation occurs using boron trifluoride etherate, acetic anhydride and dichloromethane, between −20° C. and room temperature for 3 hours. The C1-Acetate of AMod1 was then hydrolyzed and methylated in two steps to give the diacetate AMod3. That is, first AMod1 was reacted with trimethylsilyl iodide and mixed at room temperature for 2 hours, then reacted with and tetrabutyl ammonium iodide. This mixture was reacted with diisoproylethylamine and methanol and stirred for 16 hours at room temperature, thus forming AMod3. The C4 and C6 acetates of AMod3 are hydrolyzed with sodium methoxide to give the diol Amod4. The AMod3 mixture was also subjected to mixing at room temperature for 3 hours with Dowex 50 Wx4x8-100 resin in the acid form for neutralization. This formed Amod4. The C6-hydroxyl of AMod4 is then benzoylated by treating with benzoyl chloride in pyridine at −40° C. and then allowing it to warm up to −10° C. over 2 hours to give AMod5.

Coupling of monomer AMod5 with the free C4-hydroxyl group of BMod6 was performed in the presence of BF₃.Et₂O and dichloromethane with mixing between −20° C. and room temperature for 3 hours to provide disaccharide BA1. The C4-levulinyl moiety of the disaccharide was then hydrolyzed with hydrazine to give the BA Dimer, which is suitable for subsequent coupling reactions.

Synthesis of EDC Trimer

The EDC Trimer was prepared in 10 synthetic steps from Monomer E, Monomer D and Monomer C using the following procedure:

Monomer E was prepared for coupling by opening the anhydro moiety with BF₃.Et₂O followed by acetylation of the resulting hydroxyl groups to give diacetate EMod1. This occurs by the addition of Monomer E with boron trifluoride etherate, acetic anhydride and dichloromethane at −10° C., and allowing the reaction to warm to room temperature with stirring for 3 hours. The C1-Acetate of EMod1 is then hydrolyzed to give the alcohol, EMod2. This occurs by reacting Emod1 with hydrazine acetate and dimethylformamide and mixing at room temperature for 3 hours. The C1-hydroxyl of Emod2 is then reacted with trichloroacetonitrile to give the trichloro acetamidate (TCA) derivative EMod3 suitable for coupling, which reaction also employs diazabicycloundecane and dichloromethane and mixing at room temperature for 2 hours.

Monomer D, having a free C4-hydroxyl group, was coupled with monomer EMod3 in the presence of triethylsilyl triflate with mixing at −40° C. for 2 hours to give the disaccharide ED Dimer. The acetal on ring sugar D of the ED Dimer is hydrolyzed to give the C1,C2-diol ED1. This occurs by reacting the ED Dimer with 90% trifluoro acetic acid and mixing at room temperature for 4 hours. The C1-hydroxyl moiety of ED1 was then silylated with tert-butyldiphenylsilyl chloride to give the silyl derivative ED2. The C2-hydroxyl of ED2 was then allowed to react with levulinic anhydride in the presence of dimethylaminopyridine (DMAP) and diethylisopropylamine for approximately 16 hours to give the levulinate ester ED3. The TBDPS moiety is then deprotected by removal with tert-butylammonium fluoride in acetic acid with mixing at room temperature for 3 hours to give ED4 having a C1-hydroxyl. The C1-hydroxyl moiety of ED4 was then allowed to react with trichloroacetonitrile to give the TCA derivative ED5, which is suitable for coupling.

The C1-hydroxyl moiety of ED4 is then allowed to react with trichloroacetonitrile to give the TCA derivative ED5 suitable for coupling using diazabicycloundecane and dichloromethane, and mixing at room temperature for 2 hours. Monomer C, havinga free C4-hydroxyl group, was then coupled with the disaccharide ED5 in the presence of triethylsilyl triflate and mixed at −20° C. for 2 hours to give the trisaccharide EDC Trimer.

Synthesis of the EDCBA Pentamer

The EDCBA Pentamer was prepared using the following procedure:

The preparation of EDCBA Pentamer is accomplished in two parts as follows. In part 1, the EDC Trimer, a diacetate intermediate, is prepared for the coupling reaction with Dimer BA by initially opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the tetraacetate derivative EDC1. This occurs by reacting the EDC Trimer with boron trifluoride etherate, acetic anhydride and dichlormethane and stirring between −10° C. and room temperature for 3 hours. The C1-Acetate of EDC1 is then hydrolyzed to give the alcohol, EDC2, by reacting EDC1 with benzylamine [BnNH₂] and tetrahydrofuran and mixing at −10° C. for 3 hours. The C1-hydroxyl of EDC2 is then reacted with trichloroacetonitrile and diazabicycloundecane, with mixing at room temperature for 2 hours, to give the trichloro acetamidate (TCA) derivative EDC3 suitable for coupling.

In Part 2 of the EDCBA Pentameter synthesis, the Dimer BA, having a free C4-hydroxyl group, is coupled with trisaccharide EDC3 in the presence of triethylsilyltriflate at −30° C. mixing for 2 hours to give the pentasaccharide EDCBA1. The levulinyl ester on C2 of sugar D in EDCBA1 is hydrolyzed with a mixture of deprotecting agents, hydrazine hydrate and hydrazine acetate and stiffing at room temperature for 3 hours to give the C2-hydroxyl containing intermediate EDCBA2. The C2-hydroxyl moiety on sugar D of EDCBA2 is then alkylated with dihydropyran (DHP) in the presence of camphor sulfonic acid (CSA) and tetrahydrofuran with mixing at room temperature for 3 hours to give the tetrahydropyranyl ether (THP) derivative, EDCBA Pentamer.

…………………………

A fast and effective hydrogenation process of protected pentasaccharide: A key step in the synthesis of fondaparinux sodium, Org Process Res Dev 2013, 17: 869, http://pubs.acs.org/doi/full/10.1021/op300367c

An improved method for the simultaneous removal of O-benzyl and N-carboxybenzyl groups as well as reducing azide groups to amines in protected heparin-like pentasaccharides, a key process in fondaparinux sodium synthesis, is reported. Under catalytic transfer hydrogenation conditions, using readily available and inexpensive ammonium formate, the hydrogenolysis is done in less than an hour in good yield and purity. This procedure represents a major advantage over the previously published procedures, the latter of which involve several hours/days of hydrogenation reaction under catalytic reduction using gaseous hydrogen.

Synthesis of Compound 1 (FONDAPARINUX)

………………

SYNTHESIS

WO2013003001A1

US20130005954

In the synthesis of Fondaparinux sodium, the monomers XII, XVIII, XXVII, XXXVIII, XXXXI and dimers XIX, XX, XL described herein may be made either by processes described in the art or, by a process as described herein. The XII and XVIII monomers may then linked to form a disaccharide XX, XXXIX and XXVII monomers may then linked to form a disaccharide XL, XLIII and XX dimers may then linked to form a tetrasaccharide, XLVII tetramer and XLV monomer may be linked to form a pentasaccharide (XLVIII) pentamer. The XLVIII pentamer is an intermediate that may be converted through a series of reactions to fondaparinux sodium. This strategy described herein provides an efficient method for multi-kilogram preparation of fondaparinux in high yields and highly stereoselective purity.

Fondaparinux sodium (LIII) was prepared in 3 synthetic steps from O – S pentasaccharide (L) using the following procedure:

Fondaparinux Sodium (LIII)

Preparation of Fondaparinux sodium (LIII)—

N- sulfonation of Deprotected Pentasaccharide (LI) methyl 0-2-deoxy-3,6-di-0- sulfo-2-(sulfoamino)-a-D-glucopyranosyl-(l— >4)-0-2-0-sulfo-a-L- idopyranurosyl-( 1— >4)-2-deoxy-6-0-sulfo-2-(sulfoamino)-a-D-glucopyranoside,decasodium salt

A solution of deprotected pentasaccharide (LI) (145 gm) in water (2.54 V) was adjusted to a pH of 9.5 – 10.5 with 1 N NaOH solution. S03-pyridine complex (156 gm) was added into 3 lots every 15 min, the pH being maintained at 9.5-10.5 by automatic addition of 1 N NaOH. The mixture was stirred for 2 hrs at RT, during this aqueous NaOH (IN solution) was added to maintain pH at 9.5 – 10.5. After neutralization to pH 7 – 7.5 by addition of HC1 solution, the mixture was evaporated using vacuum. The residue was dissolved in water (1.6 L) at RT, to this solution was added acetone (1.6 L) at RT. The reaction mass was cooled to 5°C – 1 0 °C and stirred for 1 hr. The solid was filtered and washed with cold acetone: water (1 :1). The clear filtrate was distilled off completely under vacuum below 55°C. The residue was dissolved in water (1.6 L) at RT, and to this solution was added acetone(1.6 L) at RT. The mixture was cooled to 5 to 10°C and stirred for 1 hr. The solid was filtered and washed with cold acetone/water (1 :1). The clear filtrate was distilled off completely under vacuum below 55°C. The residue was dissolved in water (0.7 L) and charcoal (40 gm) was added at RT. The mixture was stirred for 30 min at RT then filtered. To the filtrate was added charcoal (40 gm) at RT. The mixture was stirred for 30 min at RT then filtered. To the filtrate was added charcoal (40 gm) at RT. The mixture was stirred for 30 min at RT then filtered. The pH of the clear filtrate was adjusted to 8.0 – 8.5 with IN NaOH solution and distilled off completely under vacuum below 55 °C. The residue was dissolved in 0.5 M NaCl solution and layered onto a column of Dowex^® 1×2 -400 resins using a gradient of NaCl solution (0.5 to 10M). The product fractions were combined and distilled off under vacuum below 55 °C up to 1 – 2 L volume. The solid was filtered off and the clear filtrate was distilled off under vacuum below 55 °C up to slurry stage and subjected to azeotropic distillation with methanol two times. The solid residue was stirred with methanol (2.13 L) at RT for 1 hr and the solid was filtered off and washed with methanol. The wet solid was again stirred with methanol (2.13 L) at RT for 1 hr and the solid was filtered off and washed with methanol. The wet solid was again stirred with methanol (2.13 L) at RT for 1 hr and the solid was filtered off and washed with methanol. The above solid was dissolved in water and the pH adjusted to 4 – 4.5 with IN HC1 solution and charcoalized three times with 26 gm of charcoal at RT for 15-30 minutes and filtered off. To the clear filtrate was added 0.39 kg of NaCl, then methanol was added (35 volume) at RT and the mixture was stirred for 15-30 minutes. The solution was decanted and the sticky mass was stirred with methanol (0.65 L) at RT for 15-30 minutes. The solid was filtered off and dissolved in water, and the pH adjusted to 8 – 8.5 with IN NaOH solution. The solution was filtered through 0.45 micron paper & distilled off completely under vacuum below 55°C. The solution was subjected to azeotropic distillation with methanol to give highly pure fondaparinux sodium (97.17 gm) (HPLC purity 99.7%).

SOR Results

Three batches of product made in accordance with the present processes provided the following stereoisomeric optical rotation results:

Specification: Between +50.0° and +60.0°.

Batch- 1 = +55.1°

Batch-2 = +55.7° Batch-3 = +55.4°.

INTERMEDIATES

Synthetic Procedures

The following abbreviations are used herein: Ac is acetyl; MS is molecular sieve; DMF is dimethyl formamide; Bn is benzyl; MDC is dichloromethane; THF is tetrahydrofuran; TFA is trifluoro acetic acid; MeOH is methanol; RT is room temperature; Ac₂O is acetic anhydride; HBr is hydrogen bromide; EtOAc is ethyl acetate; Cbz is benzyloxycarbonyl; CADS is chloro acetyl disaccharide; HDS is hydroxy disaccharide; NMP is N-methylpyrrolidone.

Methyl 3-O-benzyl-4-O-monochloro acetyl-β-L-idopyranuronate

Route of Synthesis for α-Methyl-6-o-acetyl-3-o-benzyl-2-(benzyloxy carbonyl)amino-2-deoxy-α-D-glucopyranoside

Methyl 6-O-acetyl-3-O-benzyl-2-(benzyloxy carbonyl)amino-2-deoxy-4-O-(methyl-2-O acetyl-3-O-benzyl-α-L-idopyranosyluronate)-glucopyranoside

Route of Synthesis for 1,6-Anhydro-2-azido-3-O-acetyl-2-deoxy-beta-D-glucopyranose

Route of synthesis for Methyl 2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranuronate

Route of synthesis for 3-O-Acetyl-1,6-anhydro-2-azido-4-O-2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranosyl methyluronate-beta-D-glucopyranose

(or)

3-O-Acetyl-1,6-anhydro-2-azido-2-deoxy-4-O-(methyl 2,3-di-O-benzyl-4-O-chloroacetyl-beta-D-glucopyranosyluronate)-beta-D-glucopyranose

Route of Synthesis for 1,6-Anhydro-2-azido-3,4-di-O-benzyl-2-deoxy-beta-D-glucopyranose

Synthesis of Disaccharide XLIII

Disaccharide XLIII was prepared in 2 synthetic steps from CADS sugar (XL) using the following procedure:

CADS sugar XL was acetylated at the anomeric carbon using AC₂O and TFA to give acetyl derivative XLII. This step was carried out using the reactants CADS, AC₂O and TFA, stirring in an ice water bath for about 5-24 hours, preferably 20 hours, and evaporating to residue under vacuum. Residue was recrystallized in ether. Acetyl CADS (XLII) was brominated at the anomeric carbon using titanium tetra bromide in MDC andethylacetate and stirring at 20° C.-50° C. for 6-16 hours, preferably 6 hours, to give the bromo derivative, (XLIII) after work-up and recrystallization from solvent/alcohol.

Synthesis of the Monosaccharide (XLV)

The monosaccharide (XLV) was prepared in 2 synthetic steps from monomer (XLI) using the following procedure:

Mono sugar (XLI) was acetylated at the anomeric carbon using AC₂O and TFA to give acetyl derivative (XLIV). This step was carried out using the reactants Mono sugar (XLI), AC₂O and TFA, stirring in an ice water bath for about 5-24 hours, preferably 24 hours, and evaporating to residue under vacuum. Residue was recrystallized in ether. Acetyl Mono sugar (XLIV) was brominated at the anomeric carbon using titanium tetra bromide in MDC and ethyl acetate and stirring at 20° C.-50° C. for 6-20 hours, preferably 16 hours, to give the bromo derivative, (XLV) after work-up and recrystallization from ether.

Synthesis of the Hydroxy Tetrasaccharide (XLVII)

The hydroxy tetrasaccharide (XLVII) was prepared in 2 synthetic steps from disaccharide (XLIII) and HDS (XX) using the following procedure:

Disaccharide (XLIII), was coupled with disaccharide (XX) in the presence of silver carbonate, silver per chlorate and 4 A° MS in MDC and stirred at ambient temperature for 5-12 hrs, preferably 4-6 hours, in the dark followed by work-up and purification in water/methanol to give the tetrasaccharide (XLVI). The d echloroacetylation of tetrasaccharide (XLVI) was carried out in THF, ethanol and pyridine in the presence of thiourea at reflux for 6 to 20 hrs, preferably 12 hours, to give the hydroxy tetrasaccharide (XLVIII).

Synthesis of the Pentasaccharide (XLVIII)

The pentasaccharide (XLVIII) was prepared in 2 synthetic steps from monosaccharide (XLV) and tetrasaccharide (XLVII) using the following procedure:

Monosaccharide (XLV), was coupled with tetrasaccharide (XLVII) in the presence of 2,4,6-collidine, silver triflate and 4 A° MS in MDC and stirred at −10° C. to −20° C. for 1 hr in the dark followed by work-up and purification by column chromatography to give the pentasaccharide (XLVIII).

Synthesis of OS Pentasaccharide (L)

The OS pentasaccharide (L) was prepared in 2 synthetic steps from pentasaccharide (XLVIII) using the following procedure:

Pentasaccharide (XLVIII) was deacetylated in the presence of NaOH in mixture of solvents of MDC, methanol and water at 0° C. to 35° C., for 1-2 hrs followed by work-up and distillation to obtain deacetylated pentasaccharide (XLIX) which was subjected to O-sulfonation in DMF in the presence of SO₃-trimethylamine (TMA) at 50° C. to 100° C., preferably 50° C.-55° C., for 6-24 hrs, preferably 12 hours, followed by salt removal through Sephadex® resin and column chromatography purification, then pH adjustment by dilute NaOH to give OS pentasaccharide (L).

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INTERMEDIATE

WO2013011460A1

highly pure 4-Ο-β-ϋ- glucopyranosyl- 1 ,6-anhydro- -D-glucopyranose

………………………

SYNTHESIS

WO2013115817A1

Synthesis of Fondaparinux

Fondaparinux was prepared using the following procedure:

Conversion of FPP (also referred to a Fully Protected Pentamer) to FondaparinuxSodium:

Reagents: 1. NaOH, H₂0₂, LiOH, Dioxane, RT, 24-48 h; 2. Py.S0₃, DMF, 60°C, 2h, CG-161 purification; 3. 10% Pd/C, H₂, 72h; 4. (a) Py.S0₃, NaOH, NH₄OAc, 12h, (b) HiQ NH₄OAc/ NaCl ion-exchange, Sephadex Desalt and (c) HiQ NaCl ion-exchange, Sephadex Desalt. The ester moieties in EDCBA Pentamer-CB were hydrolyzed with sodium and lithium hydroxide in the presence of hydrogen peroxide in dioxane mixing at room temperature for 24- 48 hours to give the pentasaccharide intermediate API1-CB. The five hydroxyl moieties in API1-CB were sulfated using a pyridine-sulfur trioxide complex in dimethylformamide, mixing at 60°C for 2 hours and then purified using column chromatography (CG-161), to give the pentasulfated pentasaccharide API2-CB. The intermediate API2-CB was then hydrogenated to reduce the three azides on sugars E, C and A to amines and the reductive deprotection of the six benzyl ethers to their corresponding hydroxyl groups to form the intermediate API3-CB. This transformation occurs by reacting API2-CB with 10% palladium/carbon catalyst with hydrogen gas for 72 hours. The three amines on API3-CB were then sulfated using the pyridine-sulfur trioxide complex in sodium hydroxide and ammonium acetate, allowing the reaction to proceed for 12 hours . The crude fondaparinux is purified and is subsequently converted to its salt form. The crude mixture was purified using an ion-exchange chromatographic column (HiQ resin) followed by desalting using a size exclusion resin or gel filtration (Biorad Sephadex G25) to give the final product, fondaparinux sodium.

Preparation of Fondaparinux Sodium – Step 4: N-Sulfation of API-3-CB:

Methyl 0-2-deoxy-6-0-sulfo-2-(sulfoamino)-a-D-glucopyranosyl-(l→4)-0^-D- glucopyranuronosyl-(l→4)-0-2-deoxy-3,6-di-0-sulfo-2-(sulfoamino)-a-D-glucopyranosyl- (l→4)-0-2-0-sulfo-a-L-idopyranuronosyl-(l→4)-2-deoxy-6-0-sulfo-2-(sulfoamino)-a-D- glucopyranoside, decasodium salt

To a solution of 25.4 gram (16.80 mmol, leq) of API-3-CB in 847 mL of water was slowly added 66.85 gram (446.88 mmol, 25eq) of sulfur trioxide-pyridine complex, maintaining the pH of the reaction mixture at pH 9-9.5 during the addition using 2N sodium hydroxide solution. The reaction was allowed to stir for 4 hours at pH 9.0 – 9.5. When reaction was completed, the pH was adjusted 7.0 by using 70 mL of 50 mmol Ammonium acetate solution pH -3.5. The resulting N-Sulfated Cellobiose mixture was purified using Ion-Exchange

Chromatographic Column followed by desalting using size exclusion resin to gave gram ( %) of the purified Fondaparinux Sodium form.

To a solution of 942 g (0.63 mol) of API3 in 46 L of water was slowly added 3.25 Kg (20.4 mol, 32 eq) of Sulfur trioxide-pyridine complex, maintaining the pH of the reaction mixture at pH 9-9.5 during the addition using 2 N sodium hydroxide solution. The reaction was allowed to stir for 4-6 hours at pH 9.0-9.5. When reaction was complete, the pH was adjusted to pH 7.0 using 50 mM solution of Ammonium acetate at pH 3.5. The resulting N- sulfated EDCBA(OS0₃)5(NHS0₃)3 mixture was purified using Ion-Exchange Chromatographic Column (Varian Preparative 15 cm HiQ Column) followed by desalting using a size exclusion resin or gel filtration (Biorad G25). The resulting mixture was then treated with activated charcoal and the purification by ion-exchange and desalting were repeated to give 516 g (47.6% yield) of the purified Fondaparinux sodium form.

INT

SCHEME 1 – Synthesis of Monomer A-2 & AMod5 fBuildinq Block Al

Reagents: 1. NaOMe, MeOH, RT, 2hr, 50wx resin; 2. (Bu₃Sn)₂0 (0.8equiv), ACN, MS, reflux, 3h; 3.l₂ (1.5 equiv), 5°C to RT, 2h; 4. NaH (2 equiv), DMF, p-MeOC₆H₄CH₂Br (PMB-Br, 2.5 equiv), -20°C to RT, 2h; 5. NaN₃, DMF, 120°C, 12h; 6. NaH, DMF, BnBr, 0°C to RT, 3h.; 7. BF₃.Et₂0, Ac₂0, DCM, -20°C to RT, 3h; 8. (a) TMS-I, TBAI, RT, 2h; (b) DIPEA, MeOH, 16h, RT; 9. NaOMe, Dowex 50WX8-100 resin H+ form, RT, 3h; 10. Pyridine, Bz-CI, -40°C to -10°C, 2h;

Scheme 2 – Synthesis of Monomer B-1 and BMod6 fBuildinq Block B1

Reagents: 1. NaH, BnBr, THF, DMF, 0° to 65°C, 3h; 2. 66% Acetic Acid/H₂0, 40 °C, 16h; 3. Nal0₄, (Bu)₄NBr, DCM, H₂0, Dark, 3h; 4. (PhS)₃CH, n-BuLi, THF, -78 °C, 3h; 5. CuCI₂/CuO, MeOH, H₂0, 3h; 6. 90% TFA/H₂0, DCM, RT, 2h; 7. DMF, CSA 2-methoxypropene, 0° to RT, 16hrs; MeOH, TEA. 8. Lev₂0, DIPEA, RT, 16h; 9. 90% TFA, RT, 4h; 10. Imidazole, TBDPSi-CI, RT, 3h; 11. Pyridine, BzCI, RT, 3h; 12. TBAF, RT, 3h; 13. TCA, DBU, RT, 2h; Also see, e.g., Bonnaffe et al., Tetrahedron Lett., 41, 307-311, 2000; Bonnaffe et al., Carbohydr. Res., 2003, 338, 681-686, 2003; and Seeberger et al., J. Org. Chem., 2003, 68, 7559- 7561, 2003.

……………………..

Carbohydrate Research, 2012 ,  vol. 361, p. 155 – 161

¹H NMR (D₂O) δ: 5.68 (d, J = 3.8 Hz, 1H, H-1D), 5.56 (d, J = 3.4 Hz, 1H, H-1F), 5.24 (d, J = 3.8 Hz, 1H, H-1G), 5.07 (d, J = 3.5 Hz, 1H, H-1H), 4.68 (d, J = 7.9 Hz, 1H, H-5G), 4.54 (dd, J = 11.4, 2.2 Hz, 1H, H-1E), 4.48-4.34 (m, 6H, H-6F, 6H, 6′H, 6D, 3E, 2G), 4.33-4.30 (m, 1H, H-6′F), 4.25-4.17 (m, 4H, H-4G, 3G, 6′D, 5F), 4.06-3.98 (m, 2H, H-4F, 5H), 3.94 (dd, J = 9.7, 2.2 Hz, 1H, H-5D), 3.92-3.86 (m, 2H,H-3E, H-4E), 3.85-3.80 (m, 2H, H-5E, 4H), 3.73-3.60 (m, 3H, H-3H, 3D, 4D), 3.53-3.44 (m, 2H, H-2F, H-2E), 3.47 (s, 3H, OMe), 3.34 (dd, J = 10.2, 3.7 Hz, 1H, H-2H), 3.31(dd, J = 10.2, 3.7 Hz, 1H, H-2D)

FONDAPARINUX

……………………………………..

Synthesis of intermediates

US8288515

Synthetic Procedures

The following abbreviations are used herein: Ac is acetyl; ACN is acetonitrile; MS is molecular sieves; DMF is dimethyl formamide; PMB is p-methoxybenzyl; Bn is benzyl; DCM is dichloromethane; THF is tetrahydrofuran; TFA is trifluoro acetic acid; CSA is camphor sulfonic acid; TEA is triethylamine; MeOH is methanol; DMAP is dimethylaminopyridine; RT is room temperature; CAN is ceric ammonium nitrate; Ac₂O is acetic anhydride; HBr is hydrogen bromide; TEMPO is tetramethylpiperidine-N-oxide; TBACl is tetrabutyl ammonium chloride; EtOAc is ethyl acetate; HOBT is hydroxybenzotriazole; DCC is dicyclohexylcarbodiimide; Lev is levunlinyl; TBDPS is tertiary-butyl diphenylsilyl; TCA is trichloroacetonitrile; O-TCA is O-trichloroacetimidate; Lev₂O is levulinic anhydride; DIPEA is diisopropylethylamine; Bz is benzoyl; TBAF is tetrabutylammonium fluoride; DBU is diazabicycloundecane; BF₃.Et₂O is boron trifluoride etherate; TMSI is trimethylsilyl iodide; TBAI is tetrabutylammonium iodide; TES-Tf is triethylsilyl trifluoromethanesulfonate (triethylsilyl triflate); DHP is dihydropyran; PTS is p-toluenesulfonic acid.

The monomers used in the processes described herein may be prepared as described in the art, or can be prepared using the methods described herein.

The synthesis of Monomer A-2 (CAS Registry Number 134221-42-4) has been described in the following references: Arndt et al., Organic Letters, 5(22), 4179-4182, 2003; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; and Sakairi et al., Journal of the Chemical Society, Chemical Communications, (5), 289-90, 1991, and the references cited therein, which are hereby incorporated by reference in their entireties.

Monomer C(CAS Registry Number 87326-68-9) can be synthesized using the methods described in the following references: Ganguli et al., Tetrahedron: Asymmetry, 16(2), 411-424, 2005; Izumi et al., Journal of Organic Chemistry, 62(4), 992-998, 1997; Van Boeckel et al., Recueil: Journal of the Royal Netherlands Chemical Society, 102(9), 415-16, 1983; Wessel et al.,Helvetica Chimica Acta, 72(6), 1268-77, 1989; Petitou et al., U.S. Pat. No. 4,818,816 and references cited therein, which are hereby incorporated by reference in their entireties.

Monomer E (CAS Registry Number 55682-48-9) can be synthesized using the methods described in the following literature references: Hawley et al., European Journal of Organic Chemistry, (12), 1925-1936, 2002; Dondoni et al., Journal of Organic Chemistry, 67(13), 4475-4486, 2002; Van der Klein et al., Tetrahedron, 48(22), 4649-58, 1992; Hori et al., Journal of Organic Chemistry, 54(6), 1346-53, 1989; Sakairi et al., Bulletin of the Chemical Society of Japan, 67(6), 1756-8, 1994; Tailler et al.,Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry, (23), 3163-4, (1972-1999) (1992); Paulsen et al., Chemische Berichte, 111(6), 2334-47, 1978; Dasgupta et al., Synthesis, (8), 626-8, 1988; Paulsen et al., Angewandte Chemie, 87(15), 547-8, 1975; and references cited therein, which are hereby incorporated by reference in their entireties.

Monomer B-1 (CAS Registry Number 444118-44-9) can be synthesized using the methods described in the following literature references: Lohman et al., Journal of Organic Chemistry, 68(19), 7559-7561, 2003; Orgueira et al., Chemistry—A European Journal, 9(1), 140-169, 2003; Manabe et al., Journal of the American Chemical Society, 128(33), 10666-10667, 2006; Orgueira et al., Angewandte Chemie, International Edition, 41(12), 2128-2131, 2002; and references cited therein, which are hereby incorporated by reference in their entireties.
Synthesis of Monomer D
Monomer D was prepared in 8 synthetic steps from glucose pentaacetate using the following procedure:

Pentaacetate SM-B was brominated at the anomeric carbon using HBr in acetic acid to give bromide derivative IntD1. This step was carried out using the reactants SM-B, 33% hydrogen bromide, acetic acid and dichloromethane, stirring in an ice water bath for about 3 hours and evaporating at room temperature. IntD1 was reductively cyclized with sodium borohydride and tetrabutylammonium iodide in acetonitrile using 3 Å molecular sieves as dehydrating agent and stirring at 40° C. for 16 hours to give the acetal derivative, IntD2. The three acetyl groups in IntD2 were hydrolyzed by heating with sodium methoxide in methanol at 50° C. for 3 hours and the reaction mixture was neutralized using Dowex 50WX8-100 resin (Aldrich) in the acid form to give the trihydroxy acetal derivative IntD3.

The C4 and C6 hydroxyls of IntD3 were protected by mixing with benzaldehyde dimethyl acetate and camphor sulphonic acid at 50° C. for 2 hours to give the benzylidene-acetal derivative IntD4. The free hydroxyl at the C3 position of IntD4 was deprotonated with sodium hydride in THF as solvent at 0° C. and alkylated with benzyl bromide in THF, and allowing the reaction mixture to warm to room temperature with stirring to give the benzyl ether IntD5. The benzylidene moiety of IntD5 was deprotected by adding trifluoroacetic acid in dichloromethane at 0° C. and allowing it to warm to room temperature for 16 hours to give IntD6 with a primary hydroxyl group. IntD6 was then oxidized with TEMPO (2,2,6,6-tetramethyl-1-piperidine-N-oxide) in the presence of tetrabutylammonium chloride, sodium bromide, ethyl acetate, sodium chlorate and sodium bicarbonate, with stirring at room temperature for 16 hours to form the carboxylic acid derivative IntD7. The acid IntD7 was esterified with benzyl alcohol and dicyclohexylcarbodiimide (other reactants being hydroxybenzotriazole and triethylamine) with stirring at room temperature for 16 hours to give Monomer D.

Synthesis of the BA Dimer

The BA Dimer was prepared in 12 synthetic steps from Monomer B1 and Monomer A2 using the following procedure:

The C4-hydroxyl of Monomer B-1 was levulinated using levulinic anhydride and diisopropylethylamine (DIPEA) with mixing at room temperature for 16 hours to give the levulinate ester BMod1, which was followed by hydrolysis of the acetonide with 90% trifluoroacetic acid and mixing at room temperature for 4 hours to give the diol BMod2. The C1 hydroxyl of the diol BMod2 was silylated with tert-butyldiphenylsilylchloride by mixing at room temperature for 3 hours to give silyl derivative BMod3. The C2-hydroxyl was then benzoylated with benzoyl chloride in pyridine, and mixed at room temperature for 3 hours to give compound BMod4. The silyl group on BMod4 was then deprotected with tert-butyl ammonium fluoride and mixing at room temperature for 3 hours to give the C1-hydroyl BMod5. The C1-hydroxyl is then allowed to react with trichloroacetonitrile in the presence of diazobicycloundecane (DBU) and mixing at room temperature for 2 hours to give the trichloroacetamidate (TCA) derivative BMod6, which suitable for coupling, for example with Monomer A-2.

Monomer A-2 was prepared for coupling by opening the anhydro moiety with BF₃.Et₂O followed by acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1.

Monomer A2 was prepared for the coupling reaction by opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the triacetate derivative AMod1. This transformation occurs using boron trifluoride etherate, acetic anhydride and dichloromethane, between −20° C. and room temperature for 3 hours. The C1-Acetate of AMod1 was then hydrolyzed and methylated in two steps to give the diacetate AMod3. That is, first AMod1 was reacted with trimethylsilyl iodide and mixed at room temperature for 2 hours, then reacted with and tetrabutyl ammonium iodide. This mixture was reacted with diisoproylethylamine and methanol and stirred for 16 hours at room temperature, thus forming AMod3. The C4 and C6 acetates of AMod3 are hydrolyzed with sodium methoxide to give the diol Amod4. The AMod3 mixture was also subjected to mixing at room temperature for 3 hours with Dowex 50 Wx4x8-100 resin in the acid form for neutralization. This formed Amod4. The C6-hydroxyl of AMod4 is then benzoylated by treating with benzoyl chloride in pyridine at −40° C. and then allowing it to warm up to −10° C. over 2 hours to give AMod5.

Coupling of monomer AMod5 with the free C4-hydroxyl group of BMod6 was performed in the presence of BF₃.Et₂O and dichloromethane with mixing between −20° C. and room temperature for 3 hours to provide disaccharide BA1. The C4-levulinyl moiety of the disaccharide was then hydrolyzed with hydrazine to give the BA Dimer, which is suitable for subsequent coupling reactions.

Synthesis of EDC Trimer

The EDC Trimer was prepared in 10 synthetic steps from Monomer E, Monomer D and Monomer C using the following procedure:

Monomer E was prepared for coupling by opening the anhydro moiety with BF₃.Et₂O followed by acetylation of the resulting hydroxyl groups to give diacetate EMod1. This occurs by the addition of Monomer E with boron trifluoride etherate, acetic anhydride and dichloromethane at −10° C., and allowing the reaction to warm to room temperature with stirring for 3 hours. The C1-Acetate of EMod1 is then hydrolyzed to give the alcohol, EMod2. This occurs by reacting Emod1 with hydrazine acetate and dimethylformamide and mixing at room temperature for 3 hours. The C1-hydroxyl of Emod2 is then reacted with trichloroacetonitrile to give the trichloro acetamidate (TCA) derivative EMod3 suitable for coupling, which reaction also employs diazabicycloundecane and dichloromethane and mixing at room temperature for 2 hours.

Monomer D, having a free C4-hydroxyl group, was coupled with monomer EMod3 in the presence of triethylsilyl triflate with mixing at −40° C. for 2 hours to give the disaccharide ED Dimer. The acetal on ring sugar D of the ED Dimer is hydrolyzed to give the C1,C2-diol ED1. This occurs by reacting the ED Dimer with 90% trifluoro acetic acid and mixing at room temperature for 4 hours. The C1-hydroxyl moiety of ED1 was then silylated with tert-butyldiphenylsilyl chloride to give the silyl derivative ED2. The C2-hydroxyl of ED2 was then allowed to react with levulinic anhydride in the presence of dimethylaminopyridine (DMAP) and diethylisopropylamine for approximately 16 hours to give the levulinate ester ED3. The TBDPS moiety is then deprotected by removal with tert-butylammonium fluoride in acetic acid with mixing at room temperature for 3 hours to give ED4 having a C1-hydroxyl. The C1-hydroxyl moiety of ED4 was then allowed to react with trichloroacetonitrile to give the TCA derivative ED5, which is suitable for coupling.

The C1-hydroxyl moiety of ED4 is then allowed to react with trichloroacetonitrile to give the TCA derivative ED5 suitable for coupling using diazabicycloundecane and dichloromethane, and mixing at room temperature for 2 hours. Monomer C, having a free C4-hydroxyl group, was then coupled with the disaccharide ED5 in the presence of triethylsilyl triflate and mixed at −20° C. for 2 hours to give the trisaccharide EDC Trimer.

Synthesis of the EDCBA Pentamer

The EDCBA Pentamer was prepared using the following procedure:

The preparation of EDCBA Pentamer is accomplished in two parts as follows. In part 1, the EDC Trimer, a diacetate intermediate, is prepared for the coupling reaction with Dimer BA by initially opening the anhydro moiety and acetylation of the resulting hydroxyl groups to give the tetraacetate derivative EDC1. This occurs by reacting the EDC Trimer with boron trifluoride etherate, acetic anhydride and dichlormethane and stirring between −10° C. and room temperature for 3 hours. The C1-Acetate of EDC1 is then hydrolyzed to give the alcohol, EDC2, by reacting EDC1 with benzylamine [BnNH₂] and tetrahydrofuran and mixing at −10° C. for 3 hours. The C1-hydroxyl of EDC2 is then reacted with trichloroacetonitrile and diazabicycloundecane, with mixing at room temperature for 2 hours, to give the trichloro acetamidate (TCA) derivative EDC3 suitable for coupling.

In Part 2 of the EDCBA Pentameter synthesis, the Dimer BA, having a free C4-hydroxyl group, is coupled with trisaccharide EDC3 in the presence of triethylsilyltriflate at −30° C. mixing for 2 hours to give the pentasaccharide EDCBA1. The levulinyl ester on C2 of sugar D in EDCBA1 is hydrolyzed with a mixture of deprotecting agents, hydrazine hydrate and hydrazine acetate and stiffing at room temperature for 3 hours to give the C2-hydroxyl containing intermediate EDCBA2. The C2-hydroxyl moiety on sugar D of EDCBA2 is then alkylated with dihydropyran (DHP) in the presence of camphor sulfonic acid (CSA) and tetrahydrofuran with mixing at room temperature for 3 hours to give the tetrahydropyranyl ether (THP) derivative, EDCBA Pentamer.

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Intermediates

Fondaparinux sodium Intermediates

Fondaparinux sodium N-4

……………………………….

Fondaparinux sodium N-3

114903-05-8

a-D-Glucopyranoside, Methyl O-2-azido-2-deoxy-3,4-bis-O-(phenylMethyl)-a-D-glucopyranosyl-(14) -O-2,3-bis-O-(phenylMethyl)-b-D-glucopyranuronosyl-(14)-O-2-azido- 2-deoxy-a-D-glucopyranosyl-(14)-O-3-O-(phenylMethyl)-a-L-idopyranu ronosyl-(14)-2-deoxy-2

FSC

114903-05-8

Chemical Name: O-[methyl2,3-di-O-benzyl-4-O-chloroacetyl-beta-Dglucopyranosyluronate]-( 1-4)-3-O-acetyl-1,6-anhydro-2-azido-2-deoxy-beta-D-glucopyranose

Description

CAS number 87907-02-6 Synonym O-[methyl2,3-di-O-benzyl-4-O-chloroacetyl-beta-Dglucopyranosyluronate]-(1-4)-3-O-acetyl-1,6-anhydro-2-azido-2-deoxy-beta-D-glucopyranose Molecular Formula C31H34ClN3O12 Molecular Weight 676.07

Chemical Name: 1,6-anhydro-2-azido-3,4-di-O-benzyl-2-deoxy-ß-D-glucopyranose

Description

CAS number 443916-61-8 Synonym 1,6-anhydro-2-azido-3,4-di-O-benzyl-2-deoxy-ß-D-glucopyranose Molecular Formula C20H21N3O4 Molecular Weight 367.4

Chemical Name: Methyl-6-O-acetyl-3-O-benzyl-2(benzyloxycarbonyl) amino-2-deoxy-4-O-(methyl2-O-acetyl-3-O-benzyl-alfa-L-idopyranosyl uronate)-alfa-D-glucopyranoside

Description

CAS number 114869-97-5 Synonym Methyl-6-O-acetyl-3-O-benzyl-2(benzyloxycarbonyl) amino-2-deoxy-4-O-(methyl2-O-acetyl-3-O-benzyl-alfa-L-idopyranosyl uronate)-alfa-D-glucopyranoside Molecular Formula C40H47NO15 Molecular Weight 781.8

Chemical Name: Benzyl-6-O-acetyl-3-O-benzyl-2-(benzyloxycarbonyl)amino-2-deoxy-4-O-(methyl2-Oacetyl-3-O-benzyl-alfa-L-idopyranosyluronate)-alfa-D-glucopyranoside

Description

CAS number 87907-11-7 Synonym Benzyl-6-O-acetyl-3-O-benzyl-2-(benzyloxycarbonyl)amino-2-deoxy-4-O-(methyl2-Oacetyl-3-O-benzyl-alfa-L-idopyranosyluronate)-alfa-D-glucopyranoside Molecular Formula C46H51NO15 Molecular Weight 857.33

Chemical Name: 3-O-Benzyl-1,2-O-isopropylidene-alpha-D-Glucofurasone

Description

CAS number 22529-61-9 Synonym 3-O-Benzyl-1,2-O-isopropylidene-alpha-D-Glucofurasone Molecular Formula C16H22O6

Chemical Name: Tetrasaccharide, ( Please refer Synonym )

Description

CAS number N-A Synonym Methyl-O-6-methyl-2,3-di-O-benzyl-beta-D-glucopyranouronosyl-(1->4)-3’6di-O’acetyl-2-azido-2-dexoy-alfa-D-glucopyranosyl-(1->4)-2-O-acetyl-3-O-benzyl-6-methyl-alfa-L-idopyranourinosyl-(1->4)-6-O-acetyl3-O-be nzyI-2-(benzyIoxycarbo n yl)amino-2-deoxy-alfa-D-gIucopyranoside Molecular Formula C71H82N4027 Molecular Weight 1423.42

Chemical Name: Fondaparinux Sodium N-3 Intermediate

Description

CAS number 114903-05-8 Synonym MethylO-(2-azido-3,4-di-O-benzyl-2-deoxy-a-D-glucopyranosyl)-(1-4)-O-(2,3-di-Obenzyl-ß-D-glucopyranosyluronicacid)-(1-4)-O-(2-azido-2-deoxy-a-D-glucopyranosyl)-(1-4)-O-(3-O-benzyl-a-L-idopyranosyluronic acid)-(1-4)-3-O-benzyl-2-benzyloxycarbonylamino-2-deoxy-a-D-glucopyranoside,N-3 Intermediate, Fondaparinux Molecular Formula C81H91N7O27 Molecular Weight 1593.60

References

FONDAPARINUX

• Arixtra home page
• Alchemia home page

The three specialties available in the United States – dalteparin (Fragmin, Pfizer), enoxaparin (Lovenox, Sanofi-Aventis) and tinzaparin (Innohep, Bristol-Myers Squibb) – the first two are found in Brazil, enoxaparin under the names Lovenox, Cutenox and Dripanina.

www.simplesharebuttons.comShare:

IDRAPARINUX

Nonasodium  (2S,3S,4S,5R,6R)-6-[(2R,3R,4S,5R,6R)-6-[(2R,3S,4S,5R,6R)-2-carboxy-4,5-dimethoxy-6-[(2R,3R,4S,5R,6S)-6-methoxy-4,5-disulfooxy-2-(sulfooxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-4,5-disulfooxy-2-(sulfooxymethyl)oxan-3-yl]oxy-4,5-dimethoxy-3-[(2R,3R,4S,5R,6R)-3,4,5-trimethoxy-6-(sulfooxymethyl)oxan-2-yl]oxyoxane-2-carboxylic acid |

CAS 162610-17-5 (free acid)

SANORG34006, SR-34006, SanOrg 34006, SanOrg-34006, UNII-H84IXP29FN, AC1MJ0N4, Org-34006

Methyl O-2,3,4-tri-O-methyl-6-O-sulfo-alpha-D-glucopyranosyl-(1–4)-O-2,3-di-O-methyl-beta-D-glucopyranuronosyl-(1–4)-O-2,3,6-tri-O-sulfo-alpha-D-glucopyranosyl-(1–4)-O-2,3-di-O-methyl-alpha-L-idopyranuronosyl-(1–4)-2,3,6-tri-O-sulfo-alpha-D-glucopyran

Sanofi-Syn(Originator), Organon (Codevelopment), PHASE 3

Methyl O-2,3,4-tri-O-methyl-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronic acid-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronic acid-(1→4)-O-α-D-glucopyranose

methyl O-2,3,4-tri-O-methyl-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2,3-O-di-methyl-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranoside nonakis sodium salt. [α]D²⁰ = +46.2° (c=1; water). Anomeric protons chemical shifts: 5.43; 5.37; 5.16; 5.09; and 5.09 ppm.

Idraparinux sodium, or methyl O-2,3,4-tri-O-methyl-6-O-sodium sulfonato-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronate sodium-(1→4)-O-2,3,6-tri-O-sodium sulfonato-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronate sodium-(1→4)-O-2,3,6-tri-O-sodium sulfonato-α-D-glucopyranose, is a pentasaccharide with antithrombotic activity.

The preparation of idraparinux by sulfatation of a deprotected pentasaccharide is described in Bioorganic & Medicinal Chemistry, 1994, Vol. 2, No. 11, pp. 1267-1280, and also in patent EP 0 529 715 B1.

Idraparinux sodium is an anticoagulant medication in development by Sanofi-Aventis.^[1]

It has a similar chemical structure and the same method of action as fondaparinux, but with an elimination half-life about five to six times longer (an increase from fondaparinux’s 17 hours to approximately 80 hours), which means that the drug should only need to be injected once a week.

As of July 2007, it has completed the Phase III clinical trial AMADEUS.

Idraparinux selectively blocks coagulation factor Xa.^[2]

See Heparin: Mechanism of anticoagulant action for a comparison of the mechanism of heparin, low-molecular-weight heparins, fondaparinux and idraparinux.

Idraparinux sodium is a synthetic pentasaccharide with indirect coagulation factor Xa inhibitor activity. The drug candidate had been in phase III clinical development at Sanofi (formerly known as sanofi-aventis) for the once-weekly long-term treatment and secondary prevention of venous thromboembolic events in patients with pulmonary embolism (PE) and deep vein thrombosis (DVT), as well as for the prevention of thromboembolic complications related to atrial fibrillation (AF).

However, no recent development has been reported for this research. The oligosaccharide is delivered by subcutaneous injection. Unlike other products, idraparinux is administered once weekly rather than daily, thereby increasing patient convenience.

Originally developed under a collaboration between sanofi-sventis and Akzo Nobel’s human healthcare business Organon, all rights to idraparinux were transferred to Sanofi in January 2004 in exchange for revenues based on future sales.

IDRAPARINUX

Several synthetic pentasaccharides have been developed, such as Idraparinux, where all hydroxyl groups are methylated or sulphated, as illustrated below:

Initially, the firm Organon developed a way of synthesis for the preparation of the “active pentasaccharide”. This synthesis, using the 3-0-benzyl-1 ,2-0-isopropylidene-a-D- glucofuranose as substrate (Van Boeckel et al., J. Carbohydr. Chem. 1985, 4, p.293-321 ), comprises more than 50 steps, and the inversion of configuration of the C5 carbon is carried out by the opening of an epoxide. After a step of protection followed by a bromination, the G unit is thus obtained. It is well known that the synthesis of said G unit is very tedious, due to the number of steps for obtaining such unit and the known tendency of L-idose derivatives to exist as furanoses. After being coupled to the H unit, successive steps of protection-deprotection then an oxidation reaction carried out on C6 carbon, lead to the GH disaccharide.

In the preparation of Idraparinux, the synthesis of the disaccharide GH is nearly similar to the above synthesis of early synthetic pentasaccharides. The major innovation lies in the obtaining of disaccharide EF by epimerization of disaccharide GH. The coupling of both disaccharides leads to the tetrasaccharide EFGH, which is further coupled to the D unit for obtaining said pentasaccharide. The preparation of the disaccharide EF from GH allows notably the decrease of the total number of the steps to approximatively 25 (Petitou, M.; Van Boeckel, C.A. Angew. Chem., Int.Ed. 2004, 43, p.31 18-3133).

Hence, all current syntheses of the “active pentasaccharide” comprise a large number of steps and more particularly involves the complex synthesis of key L-iduronic acid derivative (G unit). Indeed, the preparation of the G unit of the “active pentasaccharide” of heparin has always been a limiting step in the synthesis of antithrombotic heparin derivatives.

Thus, there is still a need for a new efficient process of preparation of L-iduronic acid derivative, which would not possess the drawbacks established above and would be compatible with industrial scales. Besides, there is a need for such process which would in addition lead to an improved process of preparation of the “active pentasaccharide” constituting the heparin derivatives.

• Idrabiotaparinux, developed by sanofi-aventis, is the biotinylated pentasaccharide corresponding to the structure depicted below. The pentasaccharide structure of idrabiotaparinux is the same as idraparinux, another antithrombotic agent developed by sanofi-aventis (see structure below). However in idrabiotaparinux, the presence of a biotin hook covalently linked to the first saccharidic unit enables the compound to be neutralized by avidin or streptavidin, as described in the international patent application WO 02/24754 .
• In the EQUINOX trial, which enrolled patients with DVT treated for 6 months with equimolar doses of either idrabiotaparinux or idraparinux, idrabiotaparinux, with the same anti-activated factor X pharmacological activity (hereafter “anti-Xa activity”) as idraparinux, was shown to have a similar efficacy, but, surprisingly, a better safety with less observed bleedings, in particular major bleedings.
• Therefore, the subject-matter of the invention is the use of idrabiotaparinux for the manufacture of a medicament useful for the treatment and secondary prevention of thrombotic pathologies, wherein the use of idrabiotaparinux involves a decrease in the incidence of bleedings during said treatment.
• In other words, the invention relates to the use of idrabiotaparinux as an antithrombotic treatment, wherein said use minimizes the risk of bleedings during the antithrombotic treatment. Indeed, idrabiotaparinux enables to increase the benefit-risk ratio during the antithrombotic treatment.

The L-ioduronic acid methyl ester derivative (XII) is then converted into its D-glucuronic acid methyl ester counterpart (XIII) by epimerization with NaOMe in refluxing MeOH, followed by esterification with MeI and KHCO3 in DMF.

Protection of the ester (XIII) with levulinic acid (IX) by means of DCC and DMAP in dioxane, followed by acetolysis of the anomeric center with sulfuric acid in acetic anhydride furnishes the disaccharide (XIV), which is then saponified with piperidine and subjected to reaction with trichloroacetonitrile and Cs2CO3 in THF to yield the imidate (XV).

Glycosylation of the disaccharide (XII) with the imidate (XV) by means of trimethylsilyl triflate in CH2Cl2, followed by removal of the levulinoyl group by means of hydrazine acetate, furnishes the tetrasaccharide (XVI), which is coupled with the glucosyl trichloroacetimidate (XVIII) by means of trimethylsilyl trifluoromethanesulfonate in CH2Cl2 providing the pentasaccharide (XVII).

Glucosyl imidate (XVIII) is prepared by methylation of 1,6-anhydroglucose (XIX) with MeI and NaH in DMF, followed by acetolysis with Ac2O/TFA to give compound (XX), which is treated with piperidine in THF and finally with trichloroacetonitrile in dichloromethane in the presence of Cs2CO3.

The pentasaccharide (XVII) is deprotected by saponification with LiOH in THF/H2O2, and then hydrogenated over Pd/C in tert-butanol/water to provide a fully deprotected pentamer, which is finally subjected to sulfation with triethylamine sulfur trioxide complex in DMF and converted into the corresponding sodium salt by elution in a Dowex 50 XW4-Na+ or a Mono-Q anion-exchange column.

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Glycosylation of sugar (I) with the idopyranosyl fluoride (II) by means of BF3.Et2O and molecular sieves in dichloromethane gives the disaccharide fragment (III), which is then converted into acetonide (V) by saponification of the ester functions with t-BuOK, followed by reaction with 2,2-dimethoxypropane (IV) in DMF and acidification with p-toluensulfonic acid. Methylation of acetonide (V) with MeI and NaH in DMF/MeOH provides the disaccharide (VI), which is then treated with HOAc to yield the 4′,6′-diol (VII). Selective silylation of the diol (VII) with tert-butyldimethylsilyl chloride (TBDMSCl) in pyridine leads to the 6′-O-TBDMS derivative (VIII), which is condensed with levulinic acid (IX) by means of dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) in dioxane to give the ester (X). Compound (X) is then submitted to simultaneous Jones oxidation and TBDMS removal with CrO3 and H2SO4/H2O in acetone to provide the iduronic acid derivative (XI), which is converted into the key intermediate (XII), first by esterification with MeI and KHCO3 in DMF and then by removal of the 4′-O-levulinoyl protecting group with HOAc and hydrazine hydrate in pyridine.

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US20120041189

Idraparinux sodium, or methyl O-2,3,4-tri-O-methyl-6-O-sodium sulfonato-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronate sodium-(1→4)-O-2,3,6-tri-O-sodium sulfonato-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronate sodium-(1→4)-O-2,3,6-tri-O-sodium sulfonato-α-D-glucopyranose, is a pentasaccharide with antithrombotic activity.

The preparation of idraparinux by sulfatation of a deprotected pentasaccharide is described in Bioorganic & Medicinal Chemistry, 1994, Vol. 2, No. 11, pp. 1267-1280, and also in patent EP 0 529 715 B1.

A crystalline form of the pentasaccharide methyl O-2,3,4-tri-O-methyl-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronic acid-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronic acid-(1→4)-O-α-D-glucopyranose has now been isolated. This compound in its crystalline form has proven to be very useful for the preparation of idraparinux, since it makes it possible to obtain this product in a particularly interesting chemical yield and with a significant gain in quality, the purity being improved as regards the crude product obtained, as will be detailed hereinbelow. These gains in reaction yield and in purity for the production of idraparinux are considerable advantages from an industrial viewpoint, since improving the robustness of a process is a constant cause for concern, especially in the case of large-scale syntheses.

One subject of the invention is thus the compound methyl O-2,3,4-tri-O-methyl-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronic acid-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronic glucopyranose in crystalline form.

Methyl O-2,3,4-tri-O-methyl-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronic acid-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronic acid-(1→4)-O-α-D-glucopyranose, referred to hereinbelow as the compound of formula (I), corresponds to the following formula:

The compound of formula (I) in crystalline form according to the invention has a powder X-ray diffractogram whose characteristic lines are approximately at 12.009; 7.703; 7.300; 7.129; 5.838; 4.665; 4.476 and 3.785 angströms (interplanar distances). It also has a melting point of about 203° C. (203° C.±1° C.).

EXAMPLE 1 Preparation of the Compound of Formula (I) in Crystalline Form (Scheme 1)

Methyl O-2,3,4-tri-O-methyl-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-β-D-glucopyranosyluronic acid-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranosyluronic acid-(1→4)-O-α-D-glucopyranose, referred to hereinbelow as the compound of formula (I)

1.1: Preparation of the Compound of Formula (I′)

The compound of formula (I″) is obtained, for example, according to the teaching of patent EP 0 529 715 B1 or of the articles “Bioorg. Med. Chem.” (1994, Vol. 2, No. 11, pp. 1267-1280), “Bioorg. Med. Chem. Letters” (1992, Vol. 2, No. 9, pp. 905-910) or “Magnetic Resonance in Chemistry” (2001, Vol. 39, pp. 288-293). The compound of formula (I″) (5 g, 3.06 mmol) is dissolved in acetonitrile (10 mL). Deionized water (12.2 mL) and aqueous 30% sodium hydroxide solution (4.1 g) are then added. The mixture is heated to 40° C. and maintained at this temperature for 5 hours. The reaction medium is then cooled to 20° C. and acidified to pH 6.25 with aqueous 1N hydrochloric acid solution (about 17.7 g) before extraction with MTBE of certain impurities, the saponified product remaining in the aqueous phase. The residual acetonitrile, contained in the aqueous phase, is then removed by concentration, followed by diluting with deionized water (125 mL). The saponified product is finally precipitated at pH 1.5 by adding aqueous 1N hydrochloric acid solution (about 17.6 g) at 20° C. The suspension is maintained for 4 hours at 20° C. before filtration. The wet solid is finally dried in a vacuum oven at 30° C. to give 2.93 g (93.6%) of compound of formula (I).

NMR (anomeric protons of the saccharide units D, E, F, G, H): 5.79, 5.14, 5.55, 5.92, 4.94 ppm.

1.2 Preparation of the Crude Compound of Formula (I)

The compound of formula (I′) obtained after the preceding step is dissolved in tetrahydrofuran (18 mL). Palladium-on-charcoal (0.3 g) is added. The reaction medium is hydrogenated at 0.3 bar of hydrogen (relative pressure) for 4 hours. After filtering and evaporating, 2.12 g (99%) of the crude compound of formula (I) are obtained.

1.3: Preparation of the Compound of Formula (I) in Crystalline Form Using an Isopropanol/MTBE Mixture

The crude hydrogenated product obtained after the preceding step is dissolved in isopropanol (13 mL) at 65° C., and then crystallized at room temperature. The suspension is then cooled to 40° C., followed by addition of MTBE (13 mL), and is then cooled slowly to 10° C. After maintenance at 10° C. for 2 hours, the crystalline hydrogenated product is filtered off, washed and dried. 1.66 g of the compound of formula (I) in crystalline form are thus obtained, in the form of a cream-white powder. The reaction yield for the production of the compound of formula (I) in crystalline form, from the compound of formula (I′), is 92.5%. When expressed relative to the starting compound (I″), the reaction yield for the production of the compound of formula (I) in crystalline form is 86.6%.

NMR (anomeric protons of the saccharide units D, E, F, G, H) of the compound of formula (I) in crystalline form: 5.77, 5.11, 5.51, 5.84, 5.01 ppm.

1.4: Preparation of the Compound of Formula (I) in Crystalline Form Using Isopropanol

The crude hydrogenated product obtained after step 1.2 is dissolved in isopropanol (5 volumes) at 75° C. The medium is then cooled slowly until crystals appear, according to the known standard techniques for crystallization. The process is performed, for example, by a first step of cooling at 65° C. for 1 hour, and than a second step of cooling to a final temperature of 25° C. over 4 hours or of 5° C. over 6 hours, and finally maintenance at this final temperature for 30 minutes. The suspension is then filtered and rinsed with isopropanol (2×0.1 V) and compound (I) is isolated in the form of white crystals, which appear under a microscope in the form of needles. The ¹H NMR analysis of these crystals is identical to that described after step 1.3 above.

EXAMPLE 4 Preparation of Idraparinux from the Compound of Formula (I) in Crystalline Form (Scheme 2)

The preparation of idraparinux (II) from the compound of formula (I) is summarized in Scheme 2.

The compound of formula (I) in crystalline form, as obtained according to Example 1.3, is dissolved in N,N′-dimethylformamide (6.6 mL) and then heated to 30° C. Under an inert atmosphere, 3.8 g of pyridine-sulfur trioxide complex are added slowly, followed by maintenance at 30° C. for 4 hours. The reaction medium is then poured into aqueous 23.8% sodium hydrogen carbonate solution (16.3 g) maintained at a maximum of 25° C., to obtain the compound of formula (II). The reaction medium is kept stirring for hours. The solution of sulfated product is then poured onto an MTBE/isopropanol/ethanol mixture (171 mL/70 mL/70 mL). Precipitation of the product is observed, and, after filtering off, washing and drying the cake, 4.99 g (96.8%) of compound of formula (II) are obtained, and are then purified by anion-exchange chromatography according to the usual techniques.

NMR (anomeric protons of the saccharide units D, E, F, G, H) of the compound of formula (II): 5.48, 4.68, 5.44, 5.08, 5.18 ppm.

It thus appears that the process according to the invention makes it possible to obtain idraparinux (compound of formula (II)) in a chemical yield of about 84% (precisely 83.8% according to the protocols described above) starting from the compound of formula (I″), i.e. a gain in yield of about 30% relative to the process described in patent EP 0 529 715 B1.

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EP0529715A1

methyl O-2,3,4-tri-O-methyl-6-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2,3-di-O-methyl-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranosyl-(1→4)-O-2,3-O-di-methyl-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranoside nonakis sodium salt. [α]_D²⁰ = +46.2° (c=1; water). Anomeric protons chemical shifts: 5.43; 5.37; 5.16; 5.09; and 5.09 ppm.

WAS PREPARED AS PER

Example 3

methyl O-4-O-(4-sulfoaminophenyl)-2,3,6-tri-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-methyl-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranoside nonakis sodium salt.

NOTE THIS IS ANALOGOUS PROCEDURE AND NOT SIMILAR

• Methyl O-4-O-(4-nitrophenyl)-6-O-acetyl-2,3-O-di-phenylmethyl-α-D-glucopyranosyl-(1→4)-O-(methyl 3-O-methyl-2-O-acetyl-α-L-idopyranosyluronate)-(1→4)-O-2,3,6-tri-O-acetyl-α-D-glucopyranoside (100 mg, 0.09 mmol), obtained by the known imidate coupling of the trichloroacetimidate of O-4-O-(4-nitrophenyl)-6-O-acetyl-2,3-O-di-phenylmethyl-α-D-glucopyranoside and methyl O-(methyl 3-O-methyl-2-O-acetyl-α-L-idopyranosyluronate)-(1→4)-O- 2,3,6-tri-O-acetyl-α-D-glucopyranoside, was dissolved in tetrahydrofuran (9 ml) and cooled to -5 °C. At this temperature a 30% aq. solution of hydrogen peroxide (4.5 ml) was added to the reaction mixture, and after 10 min a 1.25 M lithium hydroxide solution (4.7 ml) was added. The mixture was stirred for 1 h at -5 °C, after which time the temperature was raised to 0 °C and the mixture was stirred overnight. The reaction mixture was acidified with 6N hydrogen chloride at 0 °C to pH 1.5, after which the saponified compound was extracted with ethyl acetate. The organic layers were pooled, dried over magnesium sulfate, and evaporated to give 63 mg (84%) of methyl O-4-O-(4-nitrophenyl)-2,3-O-di-phenylmethy1-α-D-glucopyranosyl-(1→4)-O-3-O-methyl-α-L-idopyranuronosyl-(1→4)-O-α-D-glucopyranoside, which was dissolved in methanol (8 ml). 10% Pd on charcoal (63 mg) was added and the mixture hydrogenolyzed overnight. After filtration and evaporation 27 mg (50%) of methyl O-4-O-(4-aminophenyl)-α-D-glucopyranosyl-(1→4)-O-3-O-methyl-α-L-idopyranuronosyl-(1→4)-O-α-D-glucopyranoside were obtained.
  13 mg of methyl O-4-O-(4-aminophenyl)-O-α-D-glucopyranosyl-(1→4)-O-3-O-methyl-α-L-idopyranuronosyl-(1→4)-O-α-D-glucopyranoside were dissolved in 2 ml of dry N,N-dimethylformamide, and under an atmosphere of nitrogen 148 mg of triethylamine sulfurtrioxide complex were added. The mixture was stirred overnight at 50 °C, after which an aq. solution of sodium hydrogen carbonate was added under ice cooling. The mixture was stirred for 1 h at room temperature, concentrated to a small volume and desalted on a Sephadex G-10 column with water. The crude product obtained was purified by HPLC using a Mono-Q anion exchange column to give 11 mg (37%) of methyl O-4-O-(4-sulfoaminophenyl)-2,3,6-tri-O-sulfo-α-D-glucopyranosyl-(1→4)-O-3-O-methyl-2-O-sulfo-α-L-idopyranuronosyl-(1→4)-O-2,3,6-tri-O-sulfo-α-D-glucopyranoside nonakis sodium salt. [α]_D²⁰ = +52.2° (c=0.67; water). Anomeric protons chemical shifts: 5.5; 5.17; and 5.15 ppm.

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BMCL Volume 19, Issue 14, 15 July 2009, Pages 3875–3879

http://www.sciencedirect.com/science/article/pii/S0960894X0900482X

Final elaboration of the pentasaccharide 1. Reagents and conditions: (a) TMSOTf, Et₂O, 4 Å MS, rt, 66% (28α), 15% (28β); (b) CAN, CH₃CN, toluene, H₂O, rt, 72%; (c) CCl₃CN, DBU, CH₂Cl₂, rt, 98%; (d) TMSOTf, 4 Å MS, CH₂Cl₂, rt, 51% (73% based on recovery of 4); (e) Pd/C (10%), H₂, t-BuOH, H₂O, rt; (f) SO₃·Et₃N, DMF, 50 °C, 93% (2 steps).

The final elaboration of the pentasaccharide 1 was illustrated in IN ABOVE SCHEME Coupling of the glucopyranosyl trichloroacetimidate 6 with disaccharide acceptor 5 in the presence of trimethylsilyl trifluoromethylsulfonate and powdered 4 Å molecular sieves at room temperature in diethyl ether afforded the desired α-coupled trisaccharide 28α in a yield of 66%, together with 15% of the separable β-coupled product 28β. The anomeric 4-methoxyphenyl group in trisaccharide 28α was removed with CAN, and the resulting lactol was readily converted into the trisaccharide trichloroacetimidate 3. Coupling of donor 3 with the disaccharide acceptor 4 in the presence of trimethylsilyl trifluoromethylsulfonate and powdered 4 Å molecular sieves at room temperature in dichloromethane afforded the fully protected pentasaccharide 2 in 51% yield (73% based on recovery of 4). Finally, pentasaccharide 2 was subject to hydrogenolysis of the benzyl protecting groups. The highly polar product without purification was O-sulfated directly with triethylamine-sulfur trioxide complex to afford the sulfated pentasaccharide 1  in an excellent yield of 93% (for two steps).

Summarizing, the potent anti-thromboembolic pentasaccharide Idraparinux (1) was synthesized in total 51 steps and in 4% overall yield from d-glucose and methyl α-d-glucopyranoside.¹⁸ The synthetic route is convergent with a linear sequence of 27 steps, and the transformations are scalable. The 4-methoxyphenol glycoside intermediates are easy to be purified by crystallization.

Compound 1:  54.2 (c 1.0, H₂O);

¹H NMR (400 MHz, D₂O) δ 3.27 (t, J = 8.4 Hz, 1H), 3.30–3.38 (m, 2H), 3.47 (s, 3H), 3.53 (s, 3H), 3.56 (s, 6H), 3.58 (s, 3H), 3.62 (s, 3H), 3.63 (s, 3H), 3.64 (s, 6H), 3.75 (d, J = 10.0 Hz, 1H), 3.83–3.97 (m, 4H), 3.98 (t, J = 8.8 Hz, 1H), 4.06–4.18 (m, 3H), 4.19–4.45 (m, 8H), 4.56 (br t, J = 9.6 Hz, 1H), 4.65 (t, J = 9.2 Hz, 1H), 4.66 (d, J = 7.6 Hz, 1H), 5.00 (br s, 1H), 5.11 (br s, 1H), 5.17 (d, J = 3.6 Hz, 1H), 5.43 (d,J = 3.2 Hz, 1H), 5.47 (d, J = 4.0 Hz, 1H);

ESI-MS m/z 774.1 [M−8Na+6H]²⁻, 763.0; [M−9Na+7H]²⁻, 508.5 [M−9Na+6H]³⁻.

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WO2013050497A1

The process of preparation of Idraparinux having the following formula:

may comprise the following steps :

1 ) preparation a compound of formula (IXB)

(IXB) wherein R_a is methyl, R_b is methyl, R_c is methyl, T-i is benzyl, T₂ is benzyl, T₃ is benzyl and T is methyl, by the process according to the invention;

2) epimerisation of the disaccharide (IXB) so as to form disaccharide D of formula :

3) protection of the 4′-OH of D with a levulinoyl ester;

4) acetolysis of the disaccharide resulting from step 3), followed by preparation of the corresponding imidate;

5) coupling the disaccharide imidate resulting from step 4) with (IXB) obtainable by the process of the invention, wherein R_a is methyl, R_b is methyl, R_c is methyl, T-i is benzyl, T₂ is benzyl, T₃ is benzyl and T is methyl, to obtain a tetrasaccharide;

6) coupling the fully protected tetrasaccharide with a monosaccharide glycosyl imidate;

7) deprotection of the protecting groups by the successive saponification and hydrogenolysis;

8) sulfation of the hydroxyl groups.

In one embodiment, the present invention concerns a process of preparation of Idraparinux:

said process comprising the following steps:

preparation of a compound of formula (VI) such as defined above, from a compound of formula (V) such as defined above; preparation of a compound of formula (VII) such as defined above, from a compound of formula (VI) such as defined above;

preparation of a compound of formula (VIII) such as defined above, from a compound of formula (VII) such as defined above;

- preparation of a compound of formula (IX) such as defined above, from a compound of formula (VIII) such as defined above;

wherein in compounds of formulae (V), (VI), (VII), (VIII) and (IX), R-i , R₂, R3 and X are as defined above, R_a is methyl, R_b is methyl, R_c is methyl, R_d is methyl and R’ is the monosaccharide of formula :

wherein T-i is benzyl, T₂ is benzyl, T₃ is benzyl and T is methyl. The inventors advantageously found that the process of preparation of Idraparinux comprising the decarboxylation/intramolecular cyclisation tandem reaction, which allows the inversion of configuration of C5 carbon of the compound of formula (VI), is more efficient than the processes previously described in the literature. Indeed, the process according to the invention allows advantageously a significant decrease of the number of steps and thus an improvement of the overall yield. Thus, the process of preparation of Idraparinux may be carried out in industrial scales. The inventors found an efficient process of preparation of Idraparinux.

According to another object, the present invention concerns the use of compounds of formulae (V), (VI), (VI I), (VIII) and (IX), as intermediates for the preparation of Idraparinux. In particular, the present invention concerns the use of a compounds of formulae (VB), (VI B), (VI IB), (VI I IB) and (IXB), as intermediates for the preparation of Idraparinux The invention is further illustrated but not restricted by the description in the following examples. Example 1 :

Preparation of Methyl-4,6-0-benzylidene-a-D-glucopyranoside (la)

CHC1₃)

T_f = 166-167°C (litt. 165-166°C) To a solution of benzaldehyde (400 mL, 3.94 mol, 5.9 eq.) was added zinc chloride (100.3 g, 0.74 mol, 1 .1 eq.) under vigorous stirring. After homogenization of the solution methyl- a-D-glucopyranoside (129.6 g, 0.67 mol, 1.0 eq.) was added portionwise. After 16 hours stirring at room temperature the reaction mixture was diluted with diethyl ether (100 mL). The mixture was then poured dropwise and under vigorous stirring in a solution containing ice water (1 .5 L) and hexane (350 mL). The precipitate was filtered, washed with diethyl ether (3 x 300 mL) and dried under vacuum over KOH. The product was then recrystallised from CH₂CI₂ (720 mL) and washed with a Et₂0/CH₂CI₂ solution (75:25, 2 x 200 mL). The filtrate was repeatedly recrystallised five times from CH₂CI₂ to afford compound la as white crystals (136.97 g, 0.49 mol, 72%).

¹H NMR (CDCI3, 250 MHz): δ 2.35 (d, J_CH-O_H = 9.2 Hz, 1 H, OH), 2.83 (d, J_CH-O_H = 2.2 Hz, 1 H, OH), 3.46 (s, 3H, -OCH₃), 3.43-3.46 (m, 1 H, H-4), 3.63 (td, J_CH-_OH = ^_2,3 = 9.2 Hz, J_{1 2} = 3.9 Hz, 1 H, H-2), 3.70-3.81 (m, 2H, H-5, H-6), 3.93 (td, J = 9.2 Hz, J_CH-_OH = 2.2 Hz, 1 H, H- 3), 4.29 (m, 1 H, H-6 ), 4.79 (d, J_1i2 = 3.9 Hz, 1 H, H-1 ), 5.54 (s, 1 H, Ph-CH), 7.35-7.38 (m, 3H, H_Ar), 7.47-7.51 (m, 2H, H_Ar).

¹³C NMR (CDCI₃, 62.9 MHz): δ 55.6 (-OCH₃), 62.5 (C-5), 69.0 (C-6), 71.1 (C-3), 72.9 (C- 2), 81 .0 (C-4), 99.9 (C-1 ), 102.0 (Ph-CH), 126.4, 128.5, 129.4, 137.1 (6xC_Ar). IR (film) v (cm^“1): 3369 (O-H). Preparation of Methyl-2,3-di-0-methyl-4,6-0-benzylidene-a-D-glucopyranoside (Ma)

1₃)

°C)

To a solution of compound la (47.60 g, 0.17 mol, 1.0 eq.) in anhydrous THF (750 mL) under an argon atmosphere and cooled to 0°C, was added portionwise sodium hydride (60%, 16.93 g, 0.42 mol, 2.5 eq.). After 20 minutes methyl iodide was added dropwise (30 mL, 0.48 mol, 2.8 eq.) and the reaction mixture was allowed to reach room temperature. After 16 hours, methanol was added portionwise (75 mL) and the solution was stirred for another 15 minutes before being concentrated. The resulting residue was dissolved in EtOAc (400 mL) and washed with water (2 x 250 mL). The organic layer was dried (MgS0₄), filtered and concentrated. The resulting solid was dissolved in diethyl ether (1000 mL), hexane was added (400 mL) and the solvent was partially evaporated at low temperature. The crystals obtained were washed with hexane and the filtrate once again partially evaporated, filtered and the precipitate washed with hexane. The combined precipitates afforded compound Ma as white crystals (46.10 g, 0.15 mol, 88%).

¹H NMR (CDCI₃, 250 MHz): δ 3.30 (dd, J_2-3 = 9.1 Hz, J_1-2 = 3.7 Hz, 1 H, H-2), 3.44 (s, 3H, – OCH₃), 3.49-3.87 (m, 4H, H-4, H-5, H-6, H-3), 3.55 (s, 3H, -OCH₃), 3.64 (s, 3H, -OCH₃), 4.28 (dd, J_6-6. = 9.1 Hz, J_5-6 = 3.7 Hz, 1 H, H-6 ), 4.85 (d, J_1-2 = 3.7 Hz, 1 H, H-1 ), 5.54 (s, 1 H, Ph-CH), 7.36-7.41 (m, 3H, H_Ar), 7.48-7.52 (m, 2H, H_Ar).

¹³C NMR (CDCI₃, 62.9 MHz): δ 55.4, 59.5, 61.1 (3x-OCH₃), 62.3 (C-5), 69.1 (C-6), 79.9 (C-3), 81 .5 (C-4), 82.2 (C-2), 98.5 (C-1 ), 101.4 (Ph-CH), 126.2, 128.3, 129.0, 137.4 (6xC_Ar).

Preparation of Methyl-2,3-di-0-methyl-a-D-glucopyranoside (Ilia)

1₃)

To a suspension of compound Ma (10.33 g, 33.29 mmol, 1.0 eq.) in methanol (150 mL) was added para-toluenesulfonic acid monohydrate (322 mg, 1 .69 mmol, 0.05 eq.). After 4 hours stirring at room temperature, sodium carbonate (300 mg) was added and the reaction mixture was stirred an additional 15 minutes before filtration through a pad of Celite^®. Then the filtrate was concentrated and the residue obtained was dissolved in a mixture of distilled water/diethyl ether (3:1 , 150 mL). The organic layer was extracted with water (2 x 50 mL) then the combined aqueous phases were concentrated and dried one night under vacuum over KOH. The resulting residue was recrystallised from toluene using petroleum ether as a co-solvent. The crystals obtained were washed with hexane and dried under vacuum over KOH to obtain compound Ilia as white crystals (6.63 g, 29.83 mmol, 90%).

¹H NMR (DMSO, 400 MHz): δ 3.03 (dd, J_2-3 = 9.3 Hz, J_1-2 = 3.5 Hz, 1 H, H-2), 3.12-3.20 (m, 2H, H-3, H-4), 3.27 (s, 3H, -OCH₃), 3.32 (s, 3H, -OCH₃), 3.30-3.33 (m, 1 H, H-5), 3.44 (s, 3H, -OCH3), 3.40-3.46 (m, 1 H, H-6), 3.62 (ddd, J_6-6‘ = 1 1.6 Hz, J_CH-OH = 5.7 Hz, J_5-6 = 1 ,9 Hz, 1 H, H-6′), 4.52 (t, J = 5.7 Hz, 1 H, OH), 4.78 (d, Ji_-2 = 3.5 Hz, 1 H, H-1 ), 5.09 (d,

¹³C NMR (DMSO, 100.6 MHz): δ 54.1 , 57.4, 60.0 (3x-OCH₃), 60.6 (C-6), 69.5 (C-3), 72.5 (C-5), 80.9 (C-2), 82.8 (C-4), 96.4 (C-1 ).

IR (film) v (cm^“1): 3419 (O-H).

Preparation of Methyl methyl-2,3-di-0-methyl-a-D-glucopyranosiduronate (IVa)

C1₃)

To a solution of compound Ilia (500 mg, 2.25 mmol, 1.0 eq.) in distilled water (15 mL) were successively added NaBr (50 mg, 0.49 mmol, 0.2 eq.) and TEMPO (7 mg, 0.05 mmol, 0.02 eq.). The reaction mixture was cooled with the aid of an ice bath then a solution of NaOCI (13% v/v, 5.2 mL, 9.1 mmol, 4.0 eq.) was added. After 5 hours stirring at 0°C ethanol was added (96% v/v, 8 mL), then the pH was reduced to 2-3 by addition of HCI (10 % v/v). The solvent was evaporated and the residue obtained was suspended in methanol, filtered in order to remove the remaining salts and washed several times with dichloromethane and methanol. The filtrate was concentrated then dissolved, under an argon atmosphere, in dry methanol (40 mL). para-toluenesulfonic acid (85 mg, 0.45 mmol, 0.2 eq.) was added then the reaction mixture was heated under reflux overnight. The solvent was evaporated and the residue obtained was dissolved in EtOAc (60 mL). The organic layer was washed with a 5% aqueous NaHC0₃ solution (2 ^χ 20 mL) and with brine (1 ^χ 20 mL). The aqueous phase was extracted with dichloromethane (3 ^χ 20 mL). The combined organics were dried (MgS0₄), filtered and evaporated. Column chromatography (hexane/ethyl acetate 50:50) gave compound IVa as a colourless oil (503 mg, 2.00 mmol, 89%).

¹H NMR (CDCIs, 400 MHz): δ 3.10 (d, J_CH-OH = 3.0 Hz, 1 H, OH), 3.26 (dd, J_2-3 = 9.3 Hz, J_{1 -2} = 3.4 Hz, 1 H, H-2), 3.47 (s, 3H, -OCH₃), 3.49-3.52 (m, 1 H, H-3), 3.50 (s, 3H, -OCH₃), 3.62 (s, 3H, -OCH₃), 3.74 (td, J = 9.5 Hz, J_CH-OH = 3.0 Hz, 1 H, H-4), 3.82 (s, 3H, -OCH₃), 4.14 (d, J4.5 = 9.6 Hz, 1 H, H-5), 4.91 (d, Ji_-2 = 3.4 Hz, 1 H, H-1 ).

¹³C NMR (CDCI₃, 100.6 MHz): δ 52.9, 56.0, 59.1 , 61 .3 (4x-OCH₃), 70.6 (C-5), 71.7 (C-4), 80.9 (C-2), 81.8 (C-3), 98.1 (C-1 ), 170.9 (C=0).

IR (film) v (cm^“1): 3475 (O-H), 1750 (C=0).

Preparation of Methyl methyl^-O-il’-ethoxy^’-propyn-l’-ylJ^.S-di-O-methyl-a-D- glucopyranosiduronate (Va)

To a solution of compound IVa (4.56 g, 18.21 mmol, 1.0 eq.) in chloroform (stabilised with amylene, 200 mL) were added, under an argon atmosphere, P₂0₅ (5.31 g, 36.29 mmol, 2.0 eq.) and propargylaldehyde diethylacetal (5.2 mL, 36.27 mmol, 2.0 eq.), then the reaction mixture was heated at 60°C. After 4 hours stirring, the reaction mixture was filtered through a pad of Celite^® then the solvent was removed under vacuum. The crude mixture was suspended in EtOAc (300 mL), washed with a 5% NaHC0₃ aqueous solution (1 x 30 mL) and brine (1 x 30 ml_). The organic layer was dried (MgS0₄), filtered, and evaporated. Column chromatography (gradient hexane/ethyl acetate 80:20 – 20:80) afforded compound Va as a colourless oil (4.07 g, 12.24 mmol, 67%) in a diastereomeric mixture (64:36) (the relative composition of the mixture was determined by ¹H NMR from integrations of protons EtO-CH), along with some unreacted compound IVa (1.17 g, 4.68 mmol, 26%).

¹H NMR (CDCI₃, 400 MHz): δ 1.18-1.25 (m, 3H, -OCH₂CH₃) (diastereomeric mixture), 2.56 (m, 1 H, H-C≡C-) (mixture), 3.26-3.31 (m, 1 H, H-2) (mixture), 3.43 (s, 3H, -OCH₃) (major), 3.44 (s, 3H, -OCH₃) (minor), 3.50 (s, 3H, -OCH₃) (mixture), 3.59 (s, 3H, -OCH₃) (minor), 3.62 (s, 3H, -OCH₃) (major), 3.47-3.62 (m, 2H, H-3, -OCH_aH_bCH₃) (mixture), 3.65-3.73 (m, 1 H, -OCH_aH_bCH₃) (mixture), 3.78 (s, 3H, -OCH₃) (major), 3.80 (s, 3H, -OCH₃) (minor), 3.78-3.86 (m, 1 H, H-4) (mixture), 4.15 (d, J_4-5 = 10.0 Hz, 1 H, H-5) (major), 4.18 (d, J_4-5 = 10.0 Hz, 1 H, H-5) (minor), 4.86-4.88 (m, 1 H, H-1 ) (mixture), 5.35 (d, J = 1.7 Hz, 1 H, EtO- CH) (minor), 5.58 (d, J = 1.7 Hz, 1 H, EtO-CH) (major).

¹³C NMR (CDCI₃, 100.6 MHz): δ 15.0 (-OCH₂CH₃) (mixture), 52.6 (-OCH₃) (major), 52.7 (- OCH₃) (minor), 55.8 (-OCH₃) (mixture), 59.2 (-OCH₃) (major), 59.3 (-OCH₃) (minor), 60.4 (-OCH₂CH₃) (major), 61 .3 (-OCH₂CH₃) (minor), 61.4 (-OCH₃) (mixture), 70.1 (C-5) (minor), 70.2 (C-5) (major), 74.0 (H-C≡C-) (major), 74.2 (H-C≡C-) (minor), 76.4 (C-4) (minor), 76.7 (C-4) (major), 78.6 (H-C≡C-) (minor), 78.9 (H-C≡C-) (major), 81 .5 (C-2) (major), 81 .8 (C-2) (minor), 81.9 (C-3) (minor), 82.9 (C-3) (major), 92.6 (EtO-CH) (mixture), 97.9 (C-1 ) (minor), 98.0 (C-1 ) (major), 169.6 (C=0) (major), 169.9 (C=0) (minor). Elemental analysis: Calculated: C: 54.21 ; H: 7.28. Found: C: 54.17 ; H: 7.13.

ESI-MS (pos. mode): m/z = 355 [M+Na]⁺.

IR (film) v (cm^“1): 1752 (C=0), 3266 (≡C-H). Preparation of 4-0-(1′-ethoxy-2′-propyn-1^,-yl)-1 ,2,3-tri-0-methyl-a-D-gluco- pyranosiduronic acid (Via)

To a solution of compound Va (1.12 g, 3.37 mmol, 1.0 eq.) in EtOH/H₂0 (3:1 , 100 mL) was added sodium hydroxide (156 mg, 3.90 mmol, 1 .3 eq.). After 5 hours stirring at room temperature the solvent was evaporated. The residue obtained was dissolved in water (50 mL). The pH of the aqueous layer was reduced to 2-3 with a 5% citric acid aqueous solution, then the layer was saturated with sodium chloride before extraction with dichloromethane (10 x 20 mL). If necessary the pH was adjusted by addition of more citric acid aqueous solution. The combined organics were dried (MgS0₄), filtered and removed under vacuum. Compound Via was obtained without further purification as a colourless oil (1.020 g, 3.20 mmol, 95%), in a mixture of diastereomers (75:25) (the relative composition of the mixture was determined by ¹H NMR from integrations of protons EtO-CH).

¹H NMR (CDCIs, 400 MHz): δ 1.16-1.24 (m, 3H, -OCH₂CH₃) (diastereomeric mixture), 2.59 (d, J = 1 .6 Hz, 1 H, H-C≡C-) (major), 2.62 (s I, 1 H, H-C≡C-) (minor), 3.25-3.33 (m, 1 H, H- 2), 3.44 (s, 3H, -OCH₃) (mixture), 3.51 (s, 3H, -OCH₃) (mixture), 3.62 (s, 3H, -OCH₃) (mixture), 3.54-3.62 (m, 2H, H-3, -OCH_aH_bCH₃) (mixture), 3.68-3.77 (m, 1 H, -OCH_aH_bCH₃) (mixture), 3.81-3.87 (m, 1 H, H-4) (mixture), 4.13-4.18 (m, 1 H, H-5) (mixture), 4.88-4.90 (m, 1 H, H-1 ), 5.45 (s I, 1 H, EtO-CH) (minor), 5.63 (d, J = 1.6 Hz, 1 H, EtO-CH) (major).

¹³C NMR (CDCI₃, 100.6 MHz): δ 14.9 (-OCH₂CH₃) (mixture), 55.9 (-OCH₃) (mixture), 59.2 (-OCH₃) (minor), 59.3 (-OCH₃) (major), 60.7 (-OCH₂CH₃) (mixture), 61 .2 (-OCH₃) (minor), 61.3 (-OCH₃) (major), 70.1 (C-5) (mixture), 74.3 (H-OC-) (major), 74.8 (H-OC-) (minor), 75.7 (C-4) (minor), 76.4 (C-4) (major), 78.5 (H-C≡C-) (minor), 78.8 (H-C≡C-) (major), 81.4 (C-2) (major), 81 .7 (C-2) (minor), 81 .8 (C-3) (minor), 82.9 (C-3) (major), 92.5 (EtO-CH) (mixture), 97.8 (C-1 ) (minor), 98.0 (C-1 ) (major), 173.8 (C=0) (major), 174.0 (C=0) (minor).

ESI-MS (pos. mode): m/z = 341 [M+Na]⁺. IR (film) v (cm^“1): 1751 (C=0), 3268 (≡C-H).

Preparation of Methyl-4,7-anhydro-6-deoxy-6-methylene-7-ethoxy-2,3-di-0-methyl- a-L-/^‘d -heptopyranoside (Vila)

To a solution of compound Via (1.89 g, 5.92 mmol, 1 .0 eq.) in anhydrous THF (40 mL) and cooled to 0°C, were added IBCF (0.84 mL, 6.48 mmol, 1.1 eq.) and N- methylmorpholine (0.72 mL, 6.55 mmol, 1.1 eq.). After 20 minutes stirring the flask was covered with aluminium foil, 2-mercaptopyridine /V-oxide sodium salt (1 .77 g, 1 1.80 mmol, 2.0 eq.) was added and the reaction mixture was stirred at ambient temperature. After 2 hours, anhydrous THF (80 mL) then ie f-butylthiol (0.28 mL, 2.61 mmol, 1.6 eq.) were added. The aluminium foil was removed and the reaction mixture was irradiated and heated 30 minutes with a UV lamp (300W). The thiol excess was neutralized with a NaOCI aqueous solution (13% v/v, 10 mL). The reaction mixture was concentrated then dissolved in EtOAc (100 mL), washed successively with a 5% NaHC0₃ aqueous solution (2 x 15 mL), a 5 % citric acid aqueous solution (1 x 15 mL) and brine (1 x 25 mL), then the aqueous layer was extracted with dichloromethane (2 x 20 mL). The combined organics were dried (MgS0₄), filtered and concentrated. Column chromatography (gradient dichloromethane/ethyl acetate 95:5 – 75:25) afforded compound Vila as a colourless oil (218 mg, 0.79 mmol, 48%), in a mixture of diastereomers (67:33) (the relative composition of the mixture was determined by ¹H NMR from integrations of protons H-2).

¹H NMR (CDCIs, 400 MHz): δ 1.23 (t, J = 7.1 Hz, 3H, -OCH₂CH₃) (diastereomeric mixture), 3.13 (dd, J_2-3 = 9.6 Hz, J_1-2 = 3.0 Hz, 1 H, H-2) (minor), 3.30 (dd, J_2-3 = 5.0 Hz, J_1-2 = 1.6 Hz, 1 H, H-2) (major), 3.41 (s, 3H, -OCH₃) (minor), 3.47 (s, 3H, -OCH₃) (major), 3.50 (s, 3H, -OCH₃) (mixture), 3.53 (s, 3H, -OCH₃) (major), 3.55-3.61 (m, 1 H, -OCH_aH_bCH₃) (mixture), 3.72 (dd, J_2-3 = 5.0 Hz, J_3-4 = 2.8 Hz, 1 H, H-3) (major), 3.78-3.90 (m, 1 H, – OCH_aH_bCH₃) (mixture), 3.93-4.07 (m, 2H, H-3, H-4) (mixture), 4.59 (d I, J_4-5 = 4.0 Hz, 1 H, H-5) (major), 4.62 (d, J_1-2 = 1.7 Hz, 1 H, H-1 ) (major), (td, J_4-5 = 7.9 Hz, J = 2.6 Hz, 1 H, H- 5), (minor), 4.79 (d, J_1-2 = 3.0 Hz, 1 H, H-1 ) (minor), 5.35-5.57 (m, 3H, H-7, -C=CH₂) (mixture). ¹³C NMR (CDCI3, 100.6 MHz): δ 15.3 (-OCH₂CH₃) (minor), 15.4 (-OCH₂CH₃) (major), 56.5 (-OCH3) (minor), 56.8 (-OCH₃) (major), 58.6 (-OCH₃) (major), 59.1 (-OCH₃) (minor), 59.9 (- OCH3) (major), 60.3 (-OCH₃) (minor), 63.3 (-OCH₂CH₃) (minor), 63.8 (-OCH₂CH₃) (major), 74.2 (C-5) (minor), 74.7 (C-5) (major), 76.4 (C-3) (major), 77.0 (C-4) (major), 77.7 (C-2) (major), 79.0 (C-3) (minor), 79.7 (C-4) (minor), 80.1 (C-2) (minor), 99.3 (C-1 ) (major), 99.5 (C-1 ) (minor), 102.2 (C-7) (major), 103.0 (C-7) (minor), 1 1 1.6 (-C=CH₂) (minor), 1 15.2 (- C=CH₂) (major), 147.4 (C-6) (minor), 148.1 (C-6) (major).

ESI-MS (pos. mode): m/z = 297 [M+Na]⁺.

Preparation of Methyl-4,7-anhydro-7-ethoxy-2,3-di-0-methyl-a-L-/ o-hepto- pyranosid-6-ulose (Villa)

Through a solution of compound Vila (449 mg, 1 .64 mmol, 1.0 eq.) in anhydrous dichloromethane (10 ml_), under an argon atmosphere and cooled to -78°C, was bubbled ozone (0.2 L/min, 1 10 V). When the solution had turned dark blue, oxygen was bubbled through in order to remove the excess ozone. When the solution became colorless dimethylsulfide (5 drops) was added and the solution was brought to room temperature. After 1 h15 the reaction mixture was concentrated. Column chromatography (gradient dichloromethane/ethyl acetate 95:5 – 80:20) afforded compound Villa as a white solid (364 mg, 1.32 mmol, 80%), in a mixture of diastereomers (79:21 ) (the relative composition of the mixture was determined by ¹H NMR from integrations of protons H-2).

¹H NMR (CDCI₃, 400 MHz): δ 1.24-1 .28 (m, 3H, -OCH₂CH₃) (diastereomeric mixture), 3.10 (dd, J_2-3 = 10.2 Hz, J_1-2 = 2.9 Hz, 1 H, H-2) (minor), 3.17 (dd, J_2-3 = 9.4 Hz, J_1-2 = 2.8 Hz, 1 H, H-2) (major), 3.38 (s, 3H, -OCH₃) (major), 3.42 (s, 3H, -OCH₃) (minor), 3.50 (s, 3H, – OCH₃) (mixture), 3.63 (s, 3H, -OCH₃) (major), 3.66 (s, 3H, -OCH₃) (minor), 3.48-3.73 (m, 3H, H-3 major, -OCH_aH_bCH₃ major, -OCH_aH_bCH₃ minor), 3.77-3.95 (m, 2H, -OCH_aH_bCH₃ minor, -OCH_aH_bCH₃ major), 4.07 (dd, J_2-3 = 10.2 Hz, J_3-4 = 7.7 Hz, 1 H, H-3) (minor), 4.34 (d, J4-₅ = 9.1 Hz, 1 H, H-5) (minor), 4.39-4.44 (m, 2H, H-4 minor, H-5 major), 4.50 (dd, J_3-4 = 9.5 Hz, J_4-5 = 6.2 Hz, 1 H, H-4) (major), 4.76 (d, Ji_-2 = 2.8 Hz, 1 H, H-1 ) (major), 4.79 (d, J_1-2 = 2.9 Hz, 1 H, H-1 ) (minor), 4.89 (d, J = 1 ,1 Hz, 1 H, H-7) (minor), 4.93 (s I, 1 H, H-7) (major).

¹³C NMR (CDCI₃, 100.6 MHz): δ 15.1 (-OCH₂CH₃) (minor), 15.2 (-OCH₂CH₃) (major), 56.7 (-OCH₃) (minor), 57.2 (-OCH₃) (major), 59.3 (-OCH₃) (mixture), 59.8 (-OCH₃) (major), 60.6 (-OCH₃) (minor), 65.0 (-OCH₂CH₃) (minor), 65.5 (-OCH₂CH₃) (major), 70.2 (C-5) (major), 72.4 (C-5) (minor), 75.9 (C-4) (major), 79.2 (C-4) (minor), 79.4 (C-3) (major), 79.8 (C-2 major, C-3 minor), 80.2 (C-2) (minor), 96.1 (C-7) (major), 97.2 (C-7) (minor), 98.7 (C-1 ) (major), 99.0 (C-1 ) (minor), 205.3 (C-6) (minor), 205.6 (C-6) (major).

IR (film) v (cm^“1): 1783 (C=0).

ESI-MS (pos. mode): m/z = 299 [M+Na]⁺, 331 [M+Na+MeOH]⁺.

Preparation of Methyl methyl-2,3-di-0-methyl-a-L-idopyranosiduronate (IXa)

; CHCI3)

To a solution of compound Villa (50 mg, 0.18 mmol, 1 .0 eq.) in dichloromethane (3 mL), under an argon atmosphere and cooled to 0°C, were added m-CPBA (77%, 120 mg, 0.54 mmol, 3.0 eq.) and NaHC0₃ (20 mg, 0.23 mmol, 1 .3 eq.). After 3 hours stirring the solvent was removed under vacuum. The resulting residue was dissolved in EtOAc (30 mL), extracted with distilled water (2 x 10 mL), and the aqueous phase was concentrated. The crude mixture was dissoved in methanol (10 mL), para-toluenesulfonic acid monohydrate was added (4 mg, 0.02 mmol, 0.1 eq.) then the reaction mixture was heated to reflux and the reaction monitored by ¹H NMR in deuterated methanol. After 8 hours the solvent was evaporated. The residue obtained was dissolved in DMF (5 mL) then triethylamine (28 μί, 0.20 mmol, 1 .1 eq.) and methyl iodide (56 μί, 0.90 mmol, 5 eq.) were added. After 3h30 the reaction mixture was concentrated, dissolved in EtOAc (30 mL) and the organic phase was washed with a 5% NaHC0₃ aqueous solution (2 x 10 mL), a 5% citric acid aqueous solution (2 x 10 mL) and brine (1 x 10 mL). The aqueous phase was extracted with dichloromethane (5 x 10 mL) and the combined organics were dried (MgS0₄), filtered and concentrated. Column chromatography (dichloromethane/ethyl acetate 85:15) afforded compound Xla as a colourless oil (25 mg, 0.10 mmol, 56%). ¹H NMR (CDCI3, 400 MHz): δ 3.41 (d I, J_2-3 = 3.5 Hz, 1 H, H-2), 3.47 (s, 3H, -OCH3), 3.56 (s, 3H, -OCH3), 3.57 (s, 3H, -OCH3), 3.69 (t, J_2-3 = J3-4 = 3.5 Hz, 1 H, H-3), 3.75-3.78 (m, 1 H, OH), 3.80 (s, 3H, -OCH₃), 3.97 (m, 1 H, H-4), 4.42 (d, J_4-5 = 1 .6 Hz, 1 H, H-5), 4.61 (d,

¹³C NMR (CDCI₃, 100.6 MHz): δ 52.4, 57.5, 58.4, 60.8 (4x-OCH₃), 67.7 (C-4), 74.8 (C-5), 77.2 (C-2), 77.5 (C-3), 100.9 (C-1 ), 169.6 (C=0).

Elemental analysis: Calculated: C: 48.00 ; H: 7.25. Found: C: 47.62 ; H: 7.15.

ESI-MS (pos. mode): m/z = 272 [M+Na]⁺.

IR (film) v (cm^“1): 3491 (O-H), 1765 (C=0). Example 2 :

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(2′,3′-di-0-methyl-p-D-glucopyranosyl- uronate)-a-D-glucopyranoside (IVb)

To a solution of the co

Me

(3.279 g, 5.00 mmol, 1.0 eq.) in a water/acetonitrile mixture (1 :1 , 300 mL) were added NaBr (105 mg, 1 .02 mmol, 0.2 eq.) and TEMPO (33 mg, 0.21 mmol, 0.04 eq.). The reaction mixture was cooled with the aid of an ice bath then a solution of NaOCI (13% v/v, 1 1.5 mL, 20.08 mmol, 4.0 eq.) was added. After 3 hours stirring at 0°C, NaOCI was added anew (13% v/v, 1 1 .5 mL, 20.08 mmol, 4.0 eq.). After two more hours ethanol was added (96% v/v, 20 mL), then the pH was reduced to 2-3 by addition of HCI (10% v/v). The solvent was evaporated and the residue obtained was suspended in DMF (40 mL) then triethylamine (2.8 mL, 2.032 g, 20.0 mmol, 4.0 eq.) and methyl iodide (6.2 mL, 14.136 g, 99.6 mmol, 20.0 eq.) were added. After 4 hours stirring at room temperature the solvent was evaporated and the residue obtained was dissolved in EtOAc (200 mL). The organic layer was washed with a 5% citric acid aqueous solution (1 χ 20 mL) and brine (1 χ 20 mL). The aqueous layer was extracted with dichloromethane (2 χ 20 mL). The combined organics were dried (MgS0₄), filtered and evaporated. The residue obtained was dissolved in DMF (20 mL), then triethylamine (1.4 mL, 1 .016 g, 10.0 mmol, 2.0 eq.) and methyl iodide (3.1 mL, 7.068 g, 49.8 mmol, 10.0 eq) were added. After 60 hours stirring at room temperature the solvent was evaporated and the residue obtained was dissolved in EtOAc (200 mL). The organic layer was washed with a 5% citric acid aqueous solution (2 x 20 mL) and brine (1 χ 20 mL). The organic layer was dried (MgS0₄), filtered and evaporated. Column chromatography (gradient hexane/ethyl acetate 80:20 – 50:50) gave compound IVb as a colourless oil which was dissolved in a diethyl ether/hexane mixture and evaporated at room temperature to afford a white solid (2.500 g, 3.66 mmol, 73%).

¹H NMR (CDCI₃, 400 MHz): δ 2.92 (d, 1 H), 2.93-2.98 (m, 2H), 3.41 (s, 3H), 3.48-3.76 (m, 5H), 3.51 (s, 3H), 3.60 (s, 3H), 3.63 (s, 3H), 3.87-3.98 (m, 3H), 4.36-4.41 (m, 1 H), 4.49- 5.08 (m, 6H), 4.61 (d, 1 H), 7.24-7.42 (m, 15H).

Elemental analysis: Calculated: C: 65.09 ; H: 6.79. Found: C: 65.29 ; H: 6.96.

ESI-MS (pos. mode): m/z = 705 [M+Na]⁺.

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(4′-0-(1 “-ethoxy-2″-propyn-1 “-yl)-2′,3′- di-0-methyl-p-D-glucopyranosyluronate)-a-D-glucopyranoside (Vb)

E F To a solution of compound IVb (385 mg, 0.56 mmol, 1 .0 eq.) in chloroform (stabilised with amylene, 30 mL) were added, under an argon atmosphere, P₂0₅ (410 mg, 2.80 mmol, 5.0 eq.) and propargylaldehyde diethylacetal (0.4 mL, 2.79 mmol, 5.0 eq.), then the reaction mixture was heated at reflux. After 5 hours stirring, the reaction mixture was filtered through a pad of Celite^® then the solvent was removed under vacuum. The crude mixture was suspended in EtOAc (60 mL), washed with a 5% NaHC0₃ aqueous solution (1 x 15 mL) and brine (1 x 15 mL). The organic layer was dried (MgS0₄), filtered, and evaporated. Column chromatography (gradient hexane/ethyl acetate 90:10 – 70:30) afforded compound Vb as a colourless oil (275 mg, 0.36 mmol, 64%) in a diastereomeric mixture (64:36).

¹H NMR (CDCI₃, 250 MHz): δ 1.17-1 .27 (m, 3H), 2.55 (d, 0.36H), 2.57 (d, 0.64H), 2.92- 3.08 (m, 2H), 3.38 (s, 3H), 3.49 (s, 1.92H), 3.50 (s, 1.08H), 3.57 (s, 1.08H), 3.59 (s, 1.92H), 3.60 (s, 1.92H), 3.62 (s, 1.08H), 3.44-3.97 (m, 10H), 4.35 (t, 1 H), 4.46-4.76 (m, 6H), 5.03 (d, 1 H), 5.32 (d, 0.36H), 5.56 (d, 0.64H), 7.21-7.42 (m, 15H).

Elemental analysis: Calculated: C: 65.95 ; H: 6.85. Found: C: 65.92 ; H: 6.75.

ESI-MS (pos. mode): m/z = 787 [M+Na]⁺.

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(4′-0-(1 “-ethoxy-2″-propyn-1 ” 1 ‘,2′,3′-tri-0-methyl-a-D-glucopyranosiduronic acid)-a-D-glucopyranoside (Vlb)

E F

To a solution of compound Vb (1.02 g, 1.33 mmol, 1.0 eq.) in EtOH/H₂0 (1 :1 , 100 mL) was added sodium hydroxide (82 mg, 2.05 mmol, 1.5 eq.). After 3 hours stirring at room temperature sodium hydroxide was added anew (27 mg, 0.68 mmol, 0.5 eq.). After an additional hour stirring the solvent was evaporated. The residue obtained was dissolved in water (40 mL). The pH of the aqueous layer was reduced to 2-3 with a 10% HCI aqueous solution then the layer was saturated with sodium chloride before extraction with dichloromethane (3 x 20 mL). The combined organics were dried (MgS0₄), filtered and removed under vacuum. Compound VIb was obtained without further purification as a white solid (930 mg, 1.24 mmol, 93%), in a diastereomeric mixture (63:37).

¹H NMR (CDCIs, 400 MHz): δ 1.17-1.28 (m, 3H), 2.65 (d, 0.63H), 2.68 (d, 0.37H), 2.90- 3.09 (m, 2H), 3.37 (s, 3H), 3.46 (s, 1.1 1 H), 3.57 (s, 1.89H), 3.58 (s, 1.1 1 H), 3.60 (s, 1.89H), 3.42-3.90 (m, 10H), 4.29 (d, 1 H), 4.46-4.97 (m, 7H), 5.44 (d, 0.37H), 5.61 (d, 0.63H), 7.28-7.44 (m, 15H).

ESI-MS (pos. mode): m/z = 773 [M+Na]⁺ , 795 [M-H+2Na]⁺ . ESI-MS (neg. mode): m/z = 749 [M-H]\

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(4′,7′-anhydro-6′-deoxy-6′-methylene-7′- ethoxy-2 3′-di-0-methyl-α-L-/^‘ o-heptopyranosyl)-α-D-glucopyranoside (Vllb)

To a solution of compound VIb (647 mg, 0.86 mmol, 1.0 eq.) in anhydrous THF (20 mL) and cooled to 0°C, were added IBCF (0.1 1 mL, 0.85 mmol, 1.0 eq.) and N- methylmorpholine (0.10 mL, 0.91 mmol, 1.1 eq.). After 10 minutes stirring, the flask was covered with aluminium foil, 2-mercaptopyridine /V-oxide sodium salt (512 mg, 3.43 mmol, 4.0 eq.) was added and the reaction mixture was stirred at ambient temperature. After 20 minutes anhydrous THF (100 mL) then ie f-butylthiol (0.18 mL, 1 .68 mmol, 2.0 eq.) were added. The aluminium foil was removed and the reaction mixture was irradiated and heated 15 minutes with a UV lamp (300W). The thiol excess was neutralized with a NaOCI aqueous solution (13%, 10 mL). The reaction mixture was concentrated then dissolved in EtOAc (100 mL), washed successively with a 5% NaHC0₃ aqueous solution (1 x 15 mL), a 5 % citric acid aqueous solution (1 x 15 mL) and brine (1 x 15 mL), then the aqueous layer was extracted with dichloromethane (2 x 20 mL). The combined organics were dried (MgS0₄), filtered and concentrated. Column chromatography (gradient hexane/ethyl acetate 90 :10 – 70:30) afforded compound Vllb as a colourless oil (251 mg, 0.36 mmol, 42%) in a mixture of diastereomers (61 :39).

¹H NMR (CDCI₃, 250 MHz): δ 1.18-1.29 (m, 3H), 2.90-3.07 (m, 1 H), 3.37 (s, 1.17H), 3.38 (s, 1 .83H), 3.46 (s, 3H), 3.54 (s, 1.83H), 3.60 (s, 1 .17H), 3.29-4.00 (m, 10H), 4.1 1 -4.26 (m, 1 H), 4.50-4.96 (m, 8H), 5.09-5.48 (m, 3H), 7.23-7.39 (m, 15H).

ESI-MS (pos. mode): m/z = 720 [M+Na]⁺ _.

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(4′,7′-anhydro-7′-ethoxy-2′,3′-di-0- methyl-a-L-/^‘ o-heptopyranosid-6′-ulosyl)-a-D-glucopyranoside (Vlllb)

Through a solution of compound Vllb (145 mg, 0.21 mmol, 1 .0 eq.) in anhydrous dichloromethane (10 mL), under an argon atmosphere and cooled to -78°C, was bubbled ozone (0.2 L/min, 1 10 V). When the solution had turned dark blue, oxygen was bubbled through in order to remove the excess ozone. When the solution became colorless dimethylsulfide (4 drops) was added and the solution was brought to room temperature. After 30 min stirring the reaction mixture was concentrated. Column chromatography (gradient hexane/ethyl acetate 90:10 – 60:40) afforded compound Vlllb as a white solid (100 mg, <67%) in a mixture of diastereomers (67:33).

¹H NMR (CDCI₃, 400 MHz): δ 1.21 -1 .28 (m, 3H), 2.93-3.07 (m, 1 H), 3.31-4.26 (m, 20H), 4.52-5.02 (m, 9H), 7.20-7.45 (m, 15H).

ESI-MS (pos. mode): m/z = 731 [M+Na]⁺ _.

Preparation of Methyl-2,3,6-tri-0-benzyl-4-0(methyl 2′,3′-di-0-methyl-a-L- idopyranosiduronate)-a-D-glucopyranoside (IXb)

To a solution of compound Vlllb (62 mg, 87 μηηοΙ, 1 .0 eq.) in dichloromethane (5 mL), under an argon atmosphere and cooled to 0°C, were added m-CPBA (77%, 58 mg, 259 μηηοΙ, 3.0 eq.) and NaHC0₃ (1 1 mg, 130 μηηοΙ, 1 .5 eq.). After 5 hours stirring the solvent was removed under vacuum. The reaction mixture was then dissolved in EtOAc (50 mL) and washed successively with a 5% NaHC0₃ aqueous solution (1 x 10 mL), a 5 % citric acid aqueous solution (1 x 10 mL) and brine (1 x 10 mL). The organic layer was dried (MgS0₄), filtered and concentrated. The crude mixture was dissolved in anhydrous methanol (10 mL) and sodium methoxide was added to reach pH = 10. After 30 minutes stirring at room temperature the reaction mixture was neutralized with Dowex^®, filtered through a pad of Celite^®, and concentrated. The residue obtained was dissolved in DMF (10 mL) then triethylamine (13 μί, 93 μηηοΙ, 1.1 eq.) and methyl iodide (27 μί, 434 μηηοΙ, 5.0 eq.) were added. After 2h30 stirring the reaction mixture was concentrated, dissolved in EtOAc (40 mL) and washed with a 5% citric acid aqueous solution (2 x 10 mL), a 5% NaHC0₃ aqueous solution (2 x 10 mL), and brine (1 x 10 mL). The organic layer was dried (MgS0₄), filtered and concentrated. Column chromatography (gradient hexane/ethyl acetate 60:40-50:50) afforded compound IXb as a colourless oil (12 mg, 18 μηηοΙ, 20% over two steps).

¹H NMR (CDCIs, 400 MHz): δ 3.23 (s, 3H), 3.20-3.25 (m, 1 H), 3.36 (s, 3H), 3.43 (s, 3H), 3.46 (s, 3H), 3.33-3.58 (m, 3H), 3.60-3.69 (m, 2H), 3.72-3.95 (m, 4H), 4.53-4.60 (m, 4H), 4.68-4.97 (m, 4H), 5.14 (s, 1 H), 7.24-7.37 (15H).

ESI-MS (pos. mode): m/z = 705 [M+Na]⁺ _.

……………

Volume 69, Issue 15, 15 April 2013, Pages 3149–3158

http://www.sciencedirect.com/science/article/pii/S0040402013003025

References

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This is the basic structure of capreomycin. The table below identifies the various naturally occuring analogues^{12, 14}.

	R1	R2
Capreomycin IA	OH	b-Lys
Capreomycin IB	H	b-Lys
Capreomycin IIA	OH	NH2
Capreomycin IIB	H	NH2

Introduction

Capreomycin is a metabolite of Streptomyces capreolus, it is an antimycobacterial agent – and a potent tuberlostatic antibiotic. Capreomycin is effective against a number of Gram-positive and Gram-negative organisms, but is primarily active against mycobacteria. It has been used in the treatment of certain resistant strains of Mycobacterium tuberculosis. The drug was first described in 1960 be Herr, and was subsequently found to contain two components (I and II) and later to be comprised of four (IA, IB, IIA, IIB) as shown on thestructure page.

Tuberculosis

Tuberculosis is a disease of the respiratory system, and is airbourne. The bacilli implant themselves in areas such as the lungs, renal cortex and reticuloendothelial system where there is a high partial pressure of oxygen. This is the Primary infection and does not normally affect the person whilst their immune system is intact as the bacteria lie dormant. When the immune system is depressed, the secondary reactivation occurs, and effects of the disease are seen.

This infectious disease has been known since about 1000B.C., and it stills remains the ‘leading cause of death from a single infectious disease agent’⁷. It is estimated that around eight million people contract TB every year, of which 95% are in developing countries. Deaths from the disease is estimated at 3 million people per year by the World Health Organisation. The occurance of the disease is related directly to the economic state of the country. This is because the spread of the disease is greatly assisted by poor public and personal hygiene and by overcrowding. New drugs were develoed about forty years ago allowing tuberculosis to be regarded as a curable disease. This is no longer the case, as many multidrug-resistant strains of the disease have emerged. This is where capreomycin has it uses.

There are three groups of drugs used to treat TB, which vary in their effectiveness and potential side effects.

First line drugs include: isoniazid, rifampicin and pyrazinamide. These are most effective and have the fewest potential side effects.

Second line drugs include: ethambutol, streptomycin and p-amino salicyclic acid. These are less effective and have more toxic effects.

Third line drugs include: Capreomycin, cycloserine, viomycin, kanamycin and amikacin. These are least effective and have the most toxic effects.

The third line drugs have to be used for infections with tubercle bacilli, likely to be resistant to first and second line drugs or when first and second line drugs have been abandoned because of unwanted reactions. To decrease the possibility of resistant organisms from emerging, ‘Compound Drug Therapy’ is used where a concoction of several drugs is administered.

General Physical Data

Molecular Weight	653.70
Molecular Formula	C25H43N13O8
CAS Registry number	61394-77-2
Beilstein Registry number	876587
Chemical Name	L-3,6-diamino-hexanoyl->-cyclo-[L-2,3-diamino-propionyl->-L-seryl->-L-alanyl->-2-amino-3-ureido -acryloyl->-(S)-amino-((R)-2-amino-1(3),4,5,6-tetrahydro-pyrimidin-4-yl)-acetyl-(1->N%3&)]
Auto name	3,6-diamino-hexanoic acid [12-hydroxymethyl-3-(2-imino-hexahydro-pyrimidin-4-yl)-9-methyl- 2,5,8,11,14-pentaoxo-6-ureidomethylene-1,4,7,10,13-pentaaza-cyclohexadec-15-yl]-amide

 

		Cpm IA10	Cpm IB10	Cpm IIA14	Cpm IIB14
m.p. / oC		240-5	250-3	250	252
[a]D / o		-22.0	-42.5	+9.3	-24.9
UV / nm	0.1 M HCl	269 (e 23, 400)	268 (22, 000)
	H2O	268 (23, 200)	268 (21, 900)
	0.1 M NaOH	288 (15, 800)	290 (13, 100)

According to the literature⁹the following applies to naturally occuring capreomycin:
Ratio of IA to IB    = 1.16
Capreomycin II      = 1.5%

¹³C NMR Data of Cpm IA

Carbon Number	d /  ppm
1	51.92
2	40.28
4	172.76
10	176.29
11	54.15
5, 14	55.66
	56.23
7	168.0
8	105.90
13	172.00
16	176.6
17	135.79
19	155.32
20	18.86
21	68.33
22	49.20
23	23.53
24	49.83
26	157.0 (b)
1′	172.0
2′	36.93
3′	49.26
4′	23.59
5′	29.77
6′	39.77

 

 

 

 

The included NMR data is taken from tables in the literature^{8, 14}

The ¹³C NMR data is that of Capreomycin IA only, and the carbons are numbered accordingly in red on the structure shown above.

Below are ¹H NMR tables for the four different naturally occurring forms of capreomycin, the NH protons and CH protons are given in different tables. The NH protons are again numbered on the Cpm IA structure above, but this time in blue. The CH protons are numbered according to their postion in the amino acid residue. These are also numbered in pink on the above diagram.

Chemical Shifts of CH protons in Capreomycin Analogues

Position of Amino Acid Residue		Cpm IA	Cpm IB	Cpm IIA	Cpm IIB
1	a-CH2	2.63 (dd)	2.5 (dd)
		2.85 (dd)	2.81 (dd)
	b-CH2	3.8 (m)	3.7 (m)
	g-CH2	1.8 (m)	1.8 (m)
	d-CH2	1.8 (m)	1.8 (m)
	e-CH2	3.10 (m)	3.08 (m)
2	a-CH	4.3-3.5 (m)	4.2-4.5 (m)	4.3-4.6 (m)	4.3-4.6 (m)
	b-CH2	3.3 (m)	3.3 (m)	3.3 (m)	3.3 (m)
		3.8 (m)	3.8 (m)	4.1 (m)	4.1 (m)
3	a-CH	4.86 (t)	4.67 (q)	4.84 (t)	4.68 (q)
	b-CH2	3.84 (d)		3.95 (d)
	b-CH3		1.43 (d)		1.45 (d)
4	a-CH	4.3-4.5(m)	4.2-4.5 (m)	4.3-4.5 (m)	4.3-4.5 (m)
	b-CH2	3.7-4.2 (m)	3.7-4.2 (m)	3.7-4.2 (m)	3.79 (dd)
					3.8-4.2 (m)
5	b-CH	8.04 (s)	8.03 (s)	8.05 (s)	8.04 (s)
6	a-CH	5.01 (d)	4.96 (d)	5.01 (d)	4.95 (d)
	b-CH	4.5 (m)	4.5 (m)	4.5 (m)	4.5 (m)
	g-CH2	1.6-2.3 (m)	1.6-2.3 (m)	1.6-2.3 (m)	1.6-2.3 (m)
	d-CH2	3.3 (m)	3.3 (m)	3.3 (m)	3.3 (m)

 

Chemical Shifts of NH Protons of Capreomycin Analogues

	Cpm IA	Cpm IB	Cpm IIA	Cpm IIB
1	9.33 (d)	9.72(d)	9.60 (d)	9.50 (d)
2	9.24 (d)	9.24 (d)	9.33 (d)	9.30 (d)
3	8.82 (s)	8.76 (s)	9.10 (s)	9.10 (s)
4	8.64 (d)	8.68(d)	8.73 (d)	8.73 (d)
6	8.22 (t)	8.15 (t)
7	8.10 (t)	8.15 (t)	8.19 (t)	8.08 (t)
8	7.61 (d)	7.62 (d)	7.50 (d)	7.49 (d)
9	7.46 (s)	7.42 (s)	7.44 (s)	7.44 (s)
10	7.46 (s)	7.42 s)	7.31 (s)	7.18 (s)
11	6.48 (s)	6.49 (s)	6.43 (s)	6.34 (s)
12	6.29 (s)	6.34 (s)	6.29 (s)	6.27 (s)

Using the program gNMR I attempted to plot the above data. However, this was not successful as this program can only cope with molecules with up to 23 protons. As this molecule has Capreomycin IA has 43 hydogens, the generated ¹H NMR was lacking many essential peaks, and hence was not included.

IR Spectrum of Capreomycin IA

The same process could have done for any of the other three Capreomycin anlogues. The very broad band around 2000 cm^-1 upwards is due to the presence of so many nitrogen and carbonyl groups and hence hydrogen bonding.

Cyclo[3-[[(3S)-3,6-diamino-1-oxohexyl]amino]-L-alanyl-(2Z)-3-[(aminocarbonyl)amino]-2,3-didehydroalanyl-(2S)-2-[(4R)-2-amino-3,4,5,6-tetrahydro-4-pyrimidinyl]glycyl-(2S)-2-amino-b-alanyl-L-seryl]

capreomycinIA;Cyclo[3-[[(3S)-3,6-diamino-1-oxohexyl]amino]-L-alanyl-(2Z)-3-[(aminocarbonyl)amino]-2,3-didehydroalanyl-(2S)-2-[(4R)-2-amino-1,4,5,6-tetrahydro-4-pyrimidinyl]glycyl-(2S)-2-amino-b-alanyl-L-seryl] (9CI);1,4,7,10,13-Pentaazacyclohexadecane, cyclic peptide deriv.

37280-35-6

Formula:	C25H44 N14 O8
Molecular Weight:	668.83

Properties:Crystals. Mp: 246–248^°C.
Synonyms:capreomycin IA;Cyclo[A2pr*-Ser-N3-[(3S)-3,6-diamino-1-oxohexyl]A2pr-2-[(Z)-aminocarbonylaminomethylene]Gly-2-[(4R)-2-iminohexahydropyrimidine-4-yl]Gly-]SynthesisBelow is the peptide synthesis of capreomycin IA and IB. This was taken directly from the literature¹⁰.

 

 

No chemical synthesis of capreomycin could be found in any of the literature references. However, below is a synthesis devised from the peptide synthesis shown above. This is colour coded depending on the various amino residues. Each of the amino groups is added to the molecule in sequence linked by a peptide bond to eventually form the cyclo-structure. This was designed with some help from general references^1,2,3. 

  

 

This synthesis would be identical for capreomycin IB other than the Serine-Bzl is replaced by Alanine and the synthesis works in exactly the same way.

Capreomycin 

The individual components of the capreomycin were colour coded as follows:

Red	DEA / UDA	b, b � diethoxyalanine / b - ureidodehydroalanine
Green	A2pr	a, b � diaminopropionic acid
Turquoise	Ser	Serine
Blue	Cpd	Capreomycidine
Pink	b-Lys	b-Lysine

 

The black components of the synthesis were the various protecting groups involved:

Boc	tert � butoxycarbonyl
Z	Benzyloxycarbonyl
ONSu	N-hydroxysuccinimide
Nps	o-Nitrophenylsulphenyl
NO2	Nitro	NO2
Bzl	Benzene

 

Abbreviation	Chemical Name
NMM	N-Methylmorpholine
DCC	N,N�-Dicyclohexylcarbodiimine
HOBt	l-Hydroxybenztriazole
HONSu	N-Hydroxysuccinimide
THF	Tetrahydrofuran

 

This is the synthesis of capreomycin IA. The IB form is produced in an identical fashion except that Ser � Bzl , is replaced with Ala. 

……………………..

US8044186

 

 

Capastat Sulfate (capreomycin for injection) is a polypeptide antibiotic isolated from Streptomyces capreolus. It is a complex of 4 microbiologically active components which have been characterized in part; however, complete structural determination of all the components has not been established.

Capreomycin is supplied as the disulfate salt and is soluble in water. In complete solution, it is almost colorless.

Each vial contains the equivalent of 1 g capreomycin activity.

The structural formula is as follows:

Biological Action

Capreomycin is part of a group of drugs called aminoglycosides. These act to inhibit bacterial protein synthesis. The oxygen-dependent active transport by a polyamine carrier system affects the penetration of the aminoglycosides through the cell membrane of the bacterium. Minimal action on anaerobic organisms is observed. The effect of the aminoglycosides is bactericidal and is enhanced by agents that interfere with cell wall synthesis.

Very little is known about the mechanism of action of capreomycin specifically, but it is thought to inhibit protein synthesis by binding to the 70s ribosomal unit. Other sources⁶support this theory by suggesting that capreomycin “prevents protein biosynthesis by inhibiting group I intron splicing of RNA as well as blocking translation on the bacterial ribosome via inhibition of ribosomal subunits.” It has been reported¹⁴ that the b-amino group of the A₂pr residue promotes biological potency, and that its location within the molecule is of importance.

Side Effects

This powerful antimycobacterial agent can give rise to several side effects, some of which are listed below:

The following Nephrotoxic effects are reversible once treatment is stopped, but capreomycin is not recommended for people with kidney disorders.

• Polyuria (excess urination)
• Haematuria (red blood cells in the urine)
• Proteinuria (protein in the urine)
• Nitrogen metabolism
• Electrolyte disturbances
• Anorexia
• Anaemia
• Thirst

 

Capreomycin is also Ototoxic giving the following side effects. The nerve damage is permanent.

• Deafness
• Loss of vestibular function
• Damage to the cranial nerve 8

• References:1. An Introduction to Peptide Chemistry – P.D. Bailey
  2. Organic Chemistry – Vollhardt and Schore
  3. Peptide Synthesis – M. Bodanszky, Y. Klausner and M. Ondetti
  4. Pharmacology – H.P. Rand, M.M. Dale and J.M. Ritter
  5. http://www.aidsinfonyc.org/network/access/drugs/capr.html
  6. http://rwingo1.chm.colostate.edu/group/duane/duane.html
  7. http://www.hucmlrc.howard.edu/Pharmacology/handouts/TBRCLSIS.html
  8. J. Org.Chem.,1977, 42, 8 – McGahren, Morton, Kunstmann, Ellestad
  9. Bull.W.H.O., 1972, 47(3), 343-56 – Lightbrown et al.
  10. Tetrahedron, 1978, 34(7), 912-7 – Nomoto, Teshima, Wakamiya, Shiba
  11. Tetrahedron Letters, 1976, 43, 3907-10 – Shiba, Nomoto, Teshima, Wakamiya
  12. J.Org.Chem., 1992, 57, 5214-5217 – Gould and Minott
  13. Tetrahedron Letters, 1969, 30, 2549-41 – Bycroft, Cameron, Hassanali-Walji and Johnson
  14. Bull.Chem.Soc.Jpn, 1979, 52(6), 1709-15 – Nomoto and Shiba
  15. Experimentia – 1976, 32(9), 1109-11 – Nomoto and Wakamiya
  16. Pharmazie – 1970, 25(8), 471-2 – Voigt and Maa Bared
  17. Antimicrobial Agents Chemotherapy, 1964, 522-9 – Black, Griffith and Brickler
  18. Antimicrobial Agents Chemotherapy, 1962, 201-12 – Herr
  19. www2.chemie.uni-erlangen.de/services/telespec
• 20 ”Capreomycin binds across the ribosomal subunit interface using tlyA-encoded 2′-O-methylations in 16S and 23S rRNAs”. Mol. Cell 23 (2): 173–82. July 2006. doi:10.1016/j.molcel.2006.05.044. PMID 16857584
• 21   http://www.toku-e.com/Assets/MIC/Capreomycin%20sulfate.pdf
• CAPREOMYCIN wiki

Systematic (IUPAC) name
(3S)-3,6-diamino-N-[[(2S,5S,8E,11S,15S)-15-amino-11-[(4R)-2-amino-3,4,5,6-tetrahydropyrimidin-4-yl]-8-[(carbamoylamino)methylidene]-2-(hydroxymethyl)-3,6,9,12,16-pentaoxo-1,4,7,10,13-pentazacyclohexadec-5-yl]methyl]hexanamide; (3S)-3,6-diamino-N-[[(2S,5S,8E,11S,15S)-15-amino-11-[(4R)-2-amino-3,4,5,6-tetrahydropyrimidin-4-yl]-8-[(carbamoylamino)methylidene]-2-methyl-3,6,9,12,16-pentaoxo-1,4,7,10,13-pentazacyclohexadec-5-yl]methyl]hexanamide
Clinical data
AHFS/Drugs.com	monograph
MedlinePlus	a682860
Identifiers
CAS number	11003-38-6
Chemical data
Formula	C25H44N14O8
Mol. mass	668.706 g/mol

 

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Iloperidone (Fanapt), ILO-522, HP-873, Zomaril, 133454-47-4, antipsychotic

1-[4-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone; 1-[3-(4-Acetyl-2-methoxyphenoxy)propyl]-4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidine; 4′-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3′-methoxyacetophenone

Aventis Pharma (Originator), Novartis (Licensee), Titan (Licensee)Vanda Pharmaceuticals (Licensee)

Iloperidone(Fanapt) is a monoamine directed towards acting upon and antagonizing specific neurotransmitters, particularly multiple dopamine and serotonin receptor subtypes.

Schizophrenia is a chronic, severe, and debilitating mental disorder that affects approximately 2.4 million Americans, around 1.1% of the population. The net cost of this disorder is staggering as estimates from 2002 reveal this disorder to cost $62.7 billion. A major issue with the treatment of schizophrenia is that patients show varying levels of response and tolerance to available therapies. Although the symptoms of the disease are very severe, estimates show that approximately 3 out of 4 patients discontinue medication prior to completing 18 months of treatment, many times due to the severe side effects of the approved medications.

Synthesis

J.T. Strupczewski, K.J. Bordeau, Y. Chiang, E.J. Glamkowski, P.G.
Conway, R. Corbett, H.B. Hartman, M.R. Szewczak, C.A. Wilmot andG.C. Helsley, J. Med. Chem., 38, 1119 (1995).

US 4355037
V. Miklos, WO Patent 031497 (2010).
J.T. Strupczewski, EP Patent 0402644 (1990)

The product is protected by the U.S. Pat. No. 5,364,866, U.S. Pat. No. RE 39198 E and EP 402644 B1.U.S. Pat. No. 5,364,866 and U.S. Pat. No. 5,663,449.EP 542136, EP 612318, EP 730452, JP 95501055, JP 97511215, US 5364866, US 5776963, WO 9309102, WO 9511680.US 4355037,EP 0542136; EP 0612318; EP 0730452; EP 0957102; EP 0959075; EP 0959076; EP 0963984; JP 1995501055; JP 1997511215; US 5364866; US 5776963; WO 9309102; WO 9511680

The first reported synthetic method for Iloperidone is described in patent EP 402644 A1.

In U.S. Patent US5776963 and patent family EP4 (^ 644, there is disclosed a method for preparing iloperidone,

The synthetic method reported(4, 5) for 1 involves two chemical steps: O-alkylation of acetovanillone (2) with 1-bromo-3-chloropropane (3) to obtain chloro derivative 4 followed byN-alkylation of piperidine intermediate 5 with 4. The reported process for 4 comprises O-alkylation of 2 with 3 in acetone in the presence of potassium carbonate for 20 h to provide 4as an oil after usual work up, which was then vacuum (0.1 mmHg) distilled to collect desired product 4 at 141–143 °C with around 85% yield (Scheme 1, Path A). Some of the drawbacks of this process are as follows: longer reaction time (around 20 h), formation of 6–7% of dimer impurity (10, Scheme 2), high-vacuum distillation to achieve the quality, which is always a cumbersome process at industrial scale, requiring special apparatus and skill set, and degradation and charring of some portion of product during high-vacuum distillation. Further, the next step comprises N-alkylation of 4 with 5 in N,N-dimethylformamide (DMF) in the presence of potassium carbonate to provide iloperidone (1) as a crude solid, which was purified by crystallization using ethanol to yield pure 1 with 58% yield (Scheme 1, Path A). Some of the lacunae observed with the above process includes the following: (a) low yields, (b) formation of carbamate impurity 13 (Scheme 2) in the range 15–20% due to the use of potassium carbonate, (c) ineffective purification by crystallization using ethanol to eliminate carbamate impurity below 0.15%, and (d) iloperidone obtained by the above synthetic process was beige in color.

Scheme 2. Flow Chart Representing the Formation of Impurities

A few other improved processes reported…(Improved and Efficient Process for the Production of Highly Pure Iloperidone: A Psychotropic Agent)subsequently for 1 follow the same reaction sequence (Scheme 1, Path A) using compounds 4 and 5 as key starting materials with different bases and solvents.(6-13) However, the reported processes do not address a control mechanism for impurities 8, 9, 11, and 13 (Scheme 2) formed during the synthesis of 1. In order to eliminate these impurities, the reported processes involve employment of multiple purifications using a single solvent or mixture of solvents or purification by means of formation of the acid addition salt of 1 followed by converting back to pure 1.(6-13)

The synthetic route is as follows:

The reaction of piperidine-4-carboxylic acid (I) with formic acid and acetic anhydride gives 1-formylpiperidine-4-carboxylic acid (II), which is treated with SOCl2 and acetic anhydride to yield the corresponding acyl chloride (III). The Friedel-Crafts condensation of (III) with refluxing 1,3-difluorobenzene (IV) by means of AlCl3 affords 4-(2,4-difluorobenzoyl)-1-formylpiperidine (V), which is treated with hydroxylamine in refluxing ethanol to give the corresponding oxime (VI). The cyclization of (VI) by means of NaH in hot THF/DMF yields 6-fluoro-3-(1-formylpiperidin-4-yl)-1,2-benzisoxazole (VII), which is treated with HCl in refluxing ethanol to afford 6-fluoro-3-(4-piperidyl)-1,2-benzisoxazole (VIII). Finally, this compound is condensed with 4-(3-chloropropoxy)-3-methoxyacetophenone (IX) by means of K2CO3 in hot DMF. The intermediate 4-(3-chloropropoxy)-3-methoxyacetophenone (IX) can be obtained by condensation of 4-hydroxy-3-methoxyacetophenone (IX) with 3-chcloropropyl bromide (X) by means of NaH or K2CO3 in DMF.

Iloperidone, also known as Fanapt, Fanapta, and previously known as Zomaril, is an atypical antipsychotic for the treatment ofschizophrenia.

It was approved by the U.S. Food and Drug Administration (FDA) for use in the United States on May 6, 2009.

It’s not yet approved in India.

Hoechst Marion Roussel Inc. made initial inquiries into the drug; however, in May 1996, they discontinued research, and in June 1997 gave research rights to Titan Pharmaceuticals. Titan then handed over worldwide development, manufacturing and marketing rights to Novartis in August 1998. On June 9, 2004, Titan Pharmaceuticals announced that the Phase III development rights have been acquired by Vanda Pharmaceuticals. The original launch date was scheduled for 2002. On November 27, 2007, Vanda Pharmaceuticals announced that the U.S. Food and Drug Administration (FDA) had accepted their New Drug Application for iloperidone, confirming the application is ready for FDA review and approval. On July 28, 2008, the FDA issued a “Not Approvable” letter to Vanda Pharmaceuticals concerning the drug, stating that further trials are required before a decision can be made concerning marketed usage of iloperidone.

Chemically designated as 1-[4-[3-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone, is a second generation atypical antipsychotic agent. Iloperidone, also known as Fanapt, Fanapta, and Zomaril, was approved by the U.S. Food and Drug Administration (FDA) for use in the United States on May 6, 2009 and is indicated for the acute treatment of schizophrenia in adults. Iloperidone has been shown to act as an antagonist at all tested receptors. It was found to block the sites of noradrenalin (α2C), dopamine (D2A and D3), and serotonin (5-HT1A and 5-HT6) receptors.(2) In addition, pharmacogenomic studies identified single nucleotide polymorphisms associated with an enhanced response to iloperidone during acute treatment of schizophrenia. It is considered an “atypical” antipsychotic because it displays serotonin receptor antagonism, similar to other atypical antipsychotics. The older typical antipsychotics are primarily dopamine antagonists.(3)

Iloperidone won FDA approval for use treating schizophrenia in the United States on May 6, 2009

Iloperidone (1-[4-[3-[4-(6-fluoro-1,2-benzisoxazole-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone) is an atypical new-generation antipsychotic medicament belonging to the class of piperidinyl-benzisoxazole derivatives, which is used to treat schizophrenia, bipolar disorder and other psychiatric conditions. Iloperidone acts as a serotonin/dopamine receptor antagonist (5-HT2A/D2).

Iloperidone, also known as Fanapt, Fanapta, and previously known as Zomaril, is an atypical antipsychotic drug used for the treatment of schizophrenia. The chemical name of iloperidone is l-[4-[3-[4-(6-fluoro-l,2-benzisoxazol-3-yl)-l- piperidinyl]propoxy] -3-methoxyphenyl]ethanone.

EP 0402644 patent discloses first synthetic route of synthesis of iloperidone as shown in Scheme I, which consists of alkylation reaction between l-(4-(3-chloropropoxy-3- methoxyphenyl)ethanone of the formula (II) and 6-fluoro-3-piperidin-4-yl-l ,2 benzisoxazole hydrochloride of the formula (III) in presence of potassium carbonate in N,N dimethyl formamide. The reaction has been subsequently worked up and the compound of formula (I) is extracted from water using ethyl acetate. The compound of formula (I) is purified by crystallization using ethanol. The overall yield of compound of formula (I) is 58%.

Formula (I)

SCHEME 1 Further, we have analyzed the reported synthetic route for synthesis of iloperidone; following limitations have been observed and identified in the reported synthetic route:

a) The yield obtained using said synthetic route as reported in US RE39198 is 58%. Hence, this route of synthesis is not cost efficient at commercial scale due to low yield;

b) Use of potassium carbonate as a base in reaction leads to formation of carbon dioxide as one of the side products during the reaction, which further hinders in the manufacturing process by actively participating in manufacturing process and thereby leads to the formation o

Formula (IV)

which is in the range of 15-20%, and thereby resulting in low yield of iloperidone;

c) Purification by crystallization using ethanol as a solvent is not effective in eliminating or controlling carbamate impurity below 0.15% as per the ICH guide lines for the known impurities; and

d) Iloperidone obtained by the above synthetic process is beige in colour.

CN101768154 discloses the synthesis of iloperidone by N-alkylation reaction between l-(4-(3- chloropropoxy-3-methoxyphenyl)ethanone of the formula (II) and 6-fluoro-3-piperidin-4-yl-l,2 benzisoxazole hydrochloride of the formula (III) in inorganic alkaline solution, particularly; alkali metal carbonate solution. We have analyzed the reported synthetic route for synthesis of iloperidone and have observed and identified that the use of alkaline carbonate solution leads to the formation of carbamate impurity in the range of 1 to 1.5%.

Several patents were published after, describing essentially the same synthetic way such as US5364866 and US5663449.

The synthesis of iloperidone is described in USRE39198 (corresponding to EP 0 402 644 example 3) according to the following synthesis scheme:

In agreement with said patent, the intermediate isolated, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, is reacted with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride in N,N-dimethyl formamide at 90° C. for 16 hours. When the reaction is complete, the mixture is poured into water and extracted with ethyl acetate. The crude product thus obtained is crystallised twice from ethanol to give crystallised iloperidone with a total yield of 58%.

The yield of this process is very low; moreover, the process begins with two isolated intermediates, and requires an aqueous extractive work-up step with an increase in volumes and consequent reduction in the productivity and efficiency of the process. Said process also requires a double crystallisation step to obtain a beige product. The quality levels obtained are not described in the text of the example, but a beige color does not suggest a high-quality product, as iloperidone is a white substance.

The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is disclosed in U.S. Pat. No. 4,366,162. Example 1 describes the preparation of said intermediate by reacting acetovanillone with 1-bromo-3-chloropropane in acetone with potassium carbonate. At the end of the reaction the resulting product is purified by distillation and obtained as an oily intermediate which is left to stand in order to obtain the solid intermediate.

The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is also disclosed in U.S. Pat. No. 4,810,713. Preparation 12 describes the synthesis of said intermediate from acetovanillone and 1-bromo-3-chloropropane in sodium hydroxide alkalinized water. At the end of the reaction the product obtained is extracted in toluene, the organic phases are washed with basic aqueous solutions and finally, the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is crystallised with the aid of diisopropyl ether. The intermediate isolated is then recrystallised twice from cyclohexane and twice from petroleum ether.

An alternative process for the synthesis of iloperidone is reported in CN 102070626.

Scheme 2 shows the synthesis procedure:

The decision to alkylate acetovanillone with 1-chloro-3-propanol requires an extra synthesis step (to convert the OH group to an OR leaving group) compared with the procedure reported by the combination of patents USRE39198 (EP402644) and U.S. Pat. No. 4,366,162/U.S. Pat. No. 4,810,713, making said process less efficient from the economic standpoint.

WO2011061750 discloses an alternative iloperidone synthesis process as reported in Scheme 3:

Said process uses reagents such as methyl magnesium chloride to effect the Grignard reaction to convert the aldehyde group to a secondary alcohol group, which are much more complicated to manage on an industrial scale than the synthesis methods previously described. Moreover, the oxidation reaction of the next step uses reagents such as chromic acid or potassium permanganate, which have a very high environmental impact and very low industrial applicability.

WO2011055188 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. The same patent application also gives preparation examples of the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone isolated as crystalline solid by procedures similar to those known in the literature.

CN 101824030 reports an iloperidone synthesis method similar to that of CN 102070626 which involves the same problems of inefficiency due to the additional step of inserting the leaving group required for alkylation with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

CN 101781243 discloses an alternative iloperidone synthesis process as reported in Scheme 4.

Said process is not advantageous compared with the preceding processes as the intermediate with the oxime group, due to the nature of this functional group, is particularly liable to degradation due to the action of numerous factors such as the presence of metals, acid pHs and basic pHs.

CN101768154 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

CN 101735208 describes a process for the synthesis of iloperidone comparable to the one reported in CN 101781243, namely through the intermediate with the functional oxime group.

IN 2007MU01980 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

WO 2010031497 describes an alternative iloperidone synthesis process as reported in Scheme 5.

The considerable economic disadvantage of the process reported in WO2010031497 is based on the fact that by reversing the order of alkylation and performing that of intermediate 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride first, a greater loss of yield is generated on this intermediate which, according to the literature, is more difficult to synthesise and consequently more expensive than the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, with a globally greater economic inefficiency of the iloperidone preparation process.

CN 102212063 discloses a process for the synthesis of iloperidone with the same arrangement of the synthesis steps as patent application WO 2010031497.

WO2011154860 describes a process for the synthesis of iloperidone wherein a phase transfer catalyst is used to prepare the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone which, as in all the other preparation examples previously described, is crystallised, isolated and dried before use in the next step with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. Scheme 6 shows the synthesis scheme of the process of WO2011154860.

………………………………

US20100076196

……………………………………

WO2012123963A2

EXAMPLE 1:

Tetrabutyl ammonium bromide (2.40 gm) was added to a stirred solution of Potassium hydroxide (0.724 kg) in mixture of Heptane (2.0L). and water (10.0L), followed by addition of 1- [4-(3-chloropropoxy)-3-methoxyphenyl]ethanone (2, 1.0kg) and 6-fluoro-3-piperidin-4-yl-l,2- benzisoxazole hydrochloride^, 1.1 1kg) at 30°C. This reaction mass was stirred for 15 to 20 min. The temperature of the reaction mass was raised to 70°C and was maintained for 8 to 10 hours. After completion of reaction (by TLC, Mobile Phase: Toluene/ Acetone/Ethyl acetate = 6:2:2 mL), the mixture was cooled to 30°C, diluted with dichloromethane (2.5 L) and stirred for 30 minutes. The dichloromethane layer was separated. The aqueous layer was re-extracted with dichloromethane (1.0L). The combined dichloromethane layer was washed with water (1.5L) and decolorized with activated charcoal (0.05 kg). The solvent was distilled off completely to obtain the residue. The residue obtained was dissolved in isopropyl alcohol (5.0L) at reflux temperature to obtain the clear solution. The clear solution obtained was cooled to 30°C followed by 0°C and stirred for 60 min to precipitate out crystals. The colorless crystals of compound (I) obtained were filtered. The crystalline solid was dried under vacuum (650-700 mm/Hg) to obtain pure compound (I) as a crystalline solid. HPLC analysis was performed for the crystalline solid obtained. The purity of Iloperidone, impurity profile and yield are shown in table 1 below.

Table 1 : Analysis data of iloperidone i.e. purity, yield and impurity profile.

EXAMPLE 2:

Tetrabutyl ammonium bromide (2.40 gm) was added to a stirred solution of Potassium hydroxide (0.724 kg) in mixture of Heptane (2.0L) and water (10.0L), followed by addition of 1- [4-(3-chloropropoxy)-3-methoxyphenyl]ethanone (2, 1.0kg) and 6-fluoro-3-piperidin-4-yl-l,2- benzisoxazole hydrochloride^, 1.1 1kg) at 30°C. This reaction mass was stirred for 15 to 20 min. The temperature of the reaction mass was raised to 70°C and maintained for 8 to 10 hours. After completion of reaction (by TLC, Mobile Phase: Toluene/ Acetone/Ethyl acetate = 6:2:2 mL), the mixture was cooled to 30°C, the reaction mixture was filtered to obtain wet crude iloperidone. Further, the obtained wet crude was dried at 60-65 °C under vacuum to furnish crude iloperidone (1.72 kg). The dried crude iloperidone was dissolved in isopropyl alcohol (5.0 L) at reflux temperature and decolorized with activated charcoal (0.05 kg). Obtained filtrate was cooled to 30°C followed by 0°C and stirred for 60 min to precipitate out crystals. The colorless crystals of compound (I) obtained were filtered. The crystalline solid was dried under vacuum (650-700 mm/Hg) to obtain pure compound (I) as a crystalline solid. HPLC analysis was performed for the crystalline solid obtained. The purity of Iloperidone, impurity profile and yield are shown in table 2 below.

Table 2: Analysis data of iloperidone i.e. purity, yield and impurity profile.

EXAMPLE-3:

……………………..

US20130261308

UPLC-MS [M+H+]=427

1H-NMR (in DMSO) (chemical shifts expressed in ppm with respect to the TMS signal): 2.06-1.78 (6H, m); 2.13 (2H, m); 2.49 (2H, t); 2.52 (2H, m); 2.97 (2H, m); 3.11 (1H, tt); 3.83 (3H, s); 4.12 (2H, t); 7.06 (1H, d); 7.22 (1H, m); 7.46 (1H, d); 7.61-7.58 (2H, m); 7.94 (1H, dd).

………………………………

.Improved and Efficient Process for the Production of Highly Pure Iloperidone: A Psychotropic Agent

http://pubs.acs.org/doi/full/10.1021/op400335p?prevSearch=iloperidone&searchHistoryKey=

The present work describes an improved and highly efficient process for the synthesis ofiloperidone (1), an antipsychotic agent, which is free from potential impurities. The synthesis comprises N-alkylation of 1-(4-(3-chloropropoxy)-3-methoxyphenyl)ethanone (4) with 6-fluoro-3-piperidin-4-yl-1,2-benzisoxazole hydrochloride (5) in a mixture of water and heptane as solvent and sodium hydroxide as a base in the presence of tetrabutylammonium bromide as a phase transfer catalyst to yield iloperidone (1) with a yield of around 95% and a purity of 99.80% by HPLC. The present work also describes the optimization details performed to achieve the process attributes responsible for high yield and purity.

FT-IR (KBr, λmax, cm–1): 3031, 2949, 2779, 2746, 2822, 1669, 1614, 1585, 1510, 1462, 1448, 1415, 1380, 1313, 1262, 1221, 1177, 1150, 1123, 1077, 1034, 997, 985, 955, 884, 876, 853, 812, 781, 643, 610, 569, 475.

1H NMR (CDCl3): δ 2.03–2.10 (m, 6H), 2.12–2.18 (m, 2H), 2.55–2.56 (s, 3H), 2.58–2.60 (t, 2H), 3.02–3.09 (m, 3H), 3.91 (s, 3H), 4.10–4.19 (t, 2H), 6.91–6.93 (d, 1H), 7.01–7.06 (dd, 1H), 7.21–7.24 (dd, 1H), 7.51–7.52 (d, 1H), 7.53–7.56 (dd, 1H), 7.69–7.65 (dd, 1H).

13C NMR (CDCl3): 26.02, 26.40, 30.36, 34.34, 53.36, 54.90, 55.80, 67.16, 97.04, 97.31, 110.20, 111.02, 111.98, 112.23, 117.12, 122.36, 122.46, 123.06, 130.11, 149.00, 152.66, 160.91, 162.60, 163.53, 163.66, 165.09, 198.59.

MS (ESI, m/z): 427.2 [M + H].+

Anal. Calcd (%) for C24H27FN2O4(426.48): C, 67.54; H, 6.33; found (%): C, 67.24; H, 6.18.

HPLC

HPLC analysis developed at Megafine  India using a Hypersil BDS C18 column (250 mm × 4.6 mm, particle size 5 μm); mobile phase A comprising a mixture of 5.0 mM ammonium dihydrogen orthophosphate buffer and 0.1% triethylamine; mobile phase B comprising a mixture of acetonitrile/methanol in the ratio 80:20 v/v; gradient elution: time (min)/A (v/v): B (v/v); T0.01/65:35, T8.0/65:35, T25.0/35:65, T35.0/35:65, T37.0/65:35, T45.0/65:35; flow rate 1.0 mL/min; column temperature 30 °C; wavelength 225 nm. The observed retention time of iloperidone under these chromatographic conditions is about 17.0 min.

…….

http://www.asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=25_10_2

N oxide impurity

m.p. 155-157 ºC;

FT-IR (KBr, νmax, cm-1):
3083, 2958, 2878, 1655, 1606, 1584, 1509, 1467, 1419, 1348,1273, 1223, 1182, 1143, 1121, 1032, 971, 957, 881, 857, 813,
802;

1H NMR (300 MHz, CDCl3)

δ 1.89-1.93 (m, 2H), 2.31-2.40 (m, 2H), 2.55 (s, 3H), 2.60-2.72 (m, 2H), 3.29-3.52 (m,
2H), 3.29-3.52 (m, 2H), 3.29-3.52 (m, 2H), 3.29-3.52 (m, 1H),3.85 (s, 3H), 4.23(t, 2H, J = 6.0 Hz), 7.11 (d, 1H, J = 8.4 Hz),7.30-7.36 (m, 1H), 7.62-7.65 (m, 1H), 7.71-7.74 (dd, J = 9.3and 2.0 Hz, 1H), 8.02-8.07 (dd, J = 8.7 and 5.4 Hz, 1H);

13CNMR (75 MHz, CDCl3)

δ 22.13, 24.70, 26.35, 31.49, 55.54,63.21, 67.07, 67.82, 97.51, 110.35, 111.86, 112.67, 123.11,
123.67, 129.95, 148.63, 152.22, 160.79, 163.10, 163.69,196.40;

MS (ESI, m/z): 443 [M + H]+.

Anal. calcd. (%) forC24H27N2O5F (442.19): C, 65.15; H, 6.15; N, 6.33; found (%):C, 65.11; H, 6.09; N, 6.29.

………………………

INTERMEDIATES

FANAPT is a psychotropic agent belonging to the chemical class of piperidinyl-benzisoxazole derivatives. Its chemical name is 4′-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)piperidino]propoxy]-3′-methoxyacetophenone. Its molecular formula is C24H27FN2O4 and its molecular weight is 426.48. The structural formula is:

Iloperidone is a white to off-white finely crystalline powder. It is practically insoluble in water, very slightly soluble in 0.1 N HCl and freely soluble in chloroform, ethanol, methanol, and acetonitrile.

..

1. King, D. R.; Kanavos, P. Croat. Med. J. 2002, 43, 462– 9

   [PubMed], [CAS]

2. Kalkman, H. O.; Feuerbach, D.; Lötscher, E.; Schoeffter, P. Life Sci. 2003, 1151

    [PubMed], [CAS]

3. Scott, L. J. CNS Drugs 2009, 23, 867

    [PubMed], [CAS]

4. Bjork, A. K. K.; Abramo, A. L.; Kjellberg, B. E. S. US 4366162, 1982.

5. Strupczewski, J. T.; Helsley, G. C.; Chiang, Y.; Bordeau, K. J. EP 0402644A1, 1990.

6. Ansari, S. A.; Hirpara, H. M.; Yadav, A. K.; Gianchandani, J. P. WO2012164516, 2012.

7. Azad, M. A. K.; Pandey, G.; Singh, K.; Prasad, M.; Arora, S. K. WO2012/090138 A1, 2012.

8. Dwivedi, S. D.; Patel, D. J.; Shah, A. P. WO2012/063269, 2012.

9. Athalye, S. S.; Parghi, K. D.; Ranbhan, K. J.; Sarjekar, P. B. WO2012/153341, 2012.

10. Raman, J. V.; Rane, D.; Kevat, J.; Patil, D. WO2011/154860, 2011.

11. Reguri, B. R.; Arunagiri, M.; Yarroju, P. C.; Kasiyappan, G. S.; Ponnapall, K. WO2011/055188, 2011.

12. Shiwei, Z.; Feng, J. US 2012/0172699A1, 2012.

13. Bettoni, P.; Roletto, J.; Paissoni, P. EP 2644608A1, 2013.

14. Mathad, V. T.; Solanki, P. V.; Pandit, B. S.; Uppelli, S. B. WO2012/123963 A2, 2012.

15. Strupczewski, J. T.; Allen, R. C.; Gardner, B. A.; Schmid, B. L.; Stache, U.; Glamkowski, E. J.; Jones, M. C.; Ellis, D. B.; Huger, F. P.; Dunn, R. W. J. Med. Chem. 1985, 28, 761–769

    [ACS Full Text ], [PubMed], [CAS]

    1.  20       Mucke, H. A. M.; Castañer, J. Drugs Future 2000, 25(1), 29. 
    2. (21) Steiner, G.; Bach, A.; Bialojan, S.; Greger, G.; Hege, H.-G.;.Höger, T.; Jochims, K.; Munschauer, R.; Neumann, B.; Teschendorf, H.-J.; Traut, M.; Unger, L.; Gross, G. Drugs Future 1998 23(2), 191. 
    3. (22)     Lindgren, B. O.; Nilsson, T. Acta Chem. Scand. 1973, 27, 888. [CAS]
    4. (23)     Pearl, I. A. J. Am. Chem Soc. 1946, 68, 2180.[ACS Full Text ], [CAS]

    WO2003037337A1 *	Oct 29, 2002	May 8, 2003	Markus Ahlheim	Depot formulations of iloperidone and a star polymer
    WO2008027993A2 *	Aug 29, 2007	Mar 6, 2008	Eurand Inc	Drug delivery systems comprising solid solutions of weakly basic drugs
    CN101768154A	Sep 19, 2009	Jul 7, 2010	浙江华海药业股份有限公司	New preparation method of iloperidone
    EP0402644A1	May 16, 1990	Dec 19, 1990	Hoechst-Roussel Pharmaceuticals Incorporated	N-(aryloxyalkyl)heteroarylpiperidines and -heteroarylpiperazines,a process for their preparation and their use as medicaments
    EP0542136A1 *	Nov 5, 1992	May 19, 1993	Hoechst-Roussel Pharmaceuticals Incorporated	Heteroarylpiperidines, pyrrolidines and piperazines and their use as antipsychotics and analgetics
    US5364866	Oct 30, 1992	Nov 15, 1994	Hoechst-Roussel Pharmaceuticals, Inc.	Heteroarylpiperidines, pyrrolidines and piperazines and their use as antipsychotics and analetics
    US5663449	Jun 6, 1995	Sep 2, 1997	Hoechst Marion Roussel, Inc.	Intermediate compounds in the synthesis of heteroarylpiperidines, pyrrolidines and piperazines
    USRE39198	Nov 15, 2000	Jul 18, 2006	Aventis Pharmaceuticals Inc.	Heteroarylpiperidines, pyrrolidines and piperazines and their use as antipsychotics and analgesics