WO2015155153, SYNTHESIS OF VORTIOXETINE VIA (2,4-DIMETHYLPHENYL)(2-IODOPHENYL)SULFANE INTERMEDIATE

WO2015155153,  SYNTHESIS OF VORTIOXETINE VIA (2,4-DIMETHYLPHENYL)(2-IODOPHENYL)SULFANE INTERMEDIATE

LEK PHARMACEUTICALS D.D. [SI/SI]; Verovskova 57 1526 Ljubljana (SI)
Inventors:ZUPANCIC, Borut; (SI)

Vortioxetine is disclosed as Example 1 e in WO 2003/029232 A1 and is described as being prepared analogously to Example 1 . The process used to prepare Example 1 involves the preparation of 1 -(2-((2-(trifluoromethyl)phenyl)thio)phenyl)piperazine on a solid polystyrene support, followed by decomplexation using visible light irradiation, and purification by preparative LC-MS and ion-exchange chromatography. The overall yield for the preparation of vortioxetine is described as 17%.

Several alternative palladium catalyzed processes for the preparation of vortioxetine are described in Examples 17 to 25 of WO 2007/144005 A1 . These processes describe the preparation of vortioxetine from 2,4-dimethylthiophenol and 2-bromoiodobenzene (or 1 ,2-dibromobenzene) starting materials via a 1 -(2-bromo-phenylsulfanyl)-2,4-dimethyl-benzene intermediate. Each of these processes involves the use of a palladium catalyst and a phosphine ligand.

The preparation of vortioxetine is also described by Bang-Andersen et al. in J. Med. Chem. (201 1 ), Vol. 54, 3206-3221 . Here, in a first step, te/t-butyl 4-(2-bromophenyl)piperazine-1 -carboxylate intermediate is prepared from Boc-piperazine and 2-bromoiodobenzene in a palladium catalyzed coupling reaction. te/t-Butyl 4-(2-bromophenyl)piperazine-1 -carboxylate is then reacted with 2,4-dimethylthiophenol, again in the presence of palladium catalyst and a phosphine ligand, to provide Boc-protected vortioxetine. In the final step, vortioxetine is deprotected using hydrochloric acid to give vortioxetine hydrochloride.

WO 2013/102573 A1 describes a reaction between 1 -halogen-2,4-dimethyl-phenyl, 2-halogen-thiophenol and an optionally protected piperazine in the presence of a base and a palladium catalyst consisting of a palladium source and a phosphine ligand.

Each of the above processes has disadvantages. The process described in WO 2003/029232 is low yielding and unsuitable for the large scale production of vortioxetine, whereas the processes described in WO 2007/144005 A1 , WO 2013/102573 A1 and by Bang-Andersen et al. require the use of expensive starting materials, palladium catalyst and phosphine ligand. In addition, the toxicity of palladium is well known, Liu et al. Toxicity of Palladium, Toxicology Letters, 4 (1979) 469-473, and the European Medicines Agency' s Guideline on the Specification for Residues of Metal Catalysts sets clear limits on the permitted daily exposure to palladium arising from palladium residue within drug substances, www.ema.europa.eu. Thus it would be desirable to avoid the use of a palladium catalyst in the synthesis of vortioxetine and the subsequent purification steps required to remove palladium residue from the final pharmaceutical product.

The invention is described below in further detail by embodiments, without being limited thereto.

A general concept of the process of the present invention may be represented in Scheme 1 .

Scheme 1 : General representation of the basic synthetic concept of the present invention.

Scheme 2.

X = NH₂: lb

Scheme 2: Representation of a particular synthetic embodiment of the present invention.

Compound III can also be prepared from 2,4-dimethylbenzenethiol (II) and 1 -fluoro-2-nitrobenzene (l"'a) or 1 -chloro-2-nitrobenzene (l'"b). In the first step (2,4-dimethylphenyl)(2- nitrophenyl)sulfane (III') is formed and in the second reaction step nitro group is reduced to ami

Z = F: l"'a

Z = CI: l"'b

Scheme 3: Representation of a particular synthetic embodiment of the present invention.

Example 7: Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine vortioxetine, VII)

Mixture of (2,4-dimethylphenyl)(2-iodophenyl)sulfane V (0.34 g, 1 .0 mmol), piperazine VI (0.13 g, 1 .5 mmol), K₃P0₃ (0.42 g, 2.0 mmol), Cul (19 mg, 0.1 mmol), and 2-phenylphenol (68 mg, 0.4 mmol) in dry and degassed DMSO (2 mL) was heated under nitrogen atmosphere at 120°C for 20 h. Water (10 mL) is then added and product is extracted to EtOAc (3 x 10 mL). Combined organic layers were washed with water (3 x 10 mL) and brine (2 x 10 mL) and dried over Na₂S0₄. After evaporation of the solvent crude product is purified by chromatography to afford title compound: H NMR (CDCI₃, 500 MHz) δ 1 .63 (br s, 1 H), 2.33 (s, 3H), 2.37 (s, 3H), 3.02-

3.09 (m, 8H), 6.52 (m, 1 H), 6.87 (m, 1 H), 7.04 (m, 1 H), 7.06-7.10 (m, 2H), 7.16 (m, 1 H), 7.39 (d, J= 7.8 Hz, 1 H); MS (ESI) m/z: 299 [MH]⁺.

Example 8: Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine (vortioxetine, VII)

Mixture of (2,4-dimethylphenyl)(2-iodophenyl)sulfane V (0.34 g, 1 .0 mmol), piperazine VI (0.13 g, 1 .5 mmol), K₃P0₃ (0.42 g, 2.0 mmol), Cul (19 mg, 0.1 mmol), and N,N-diethyl-2-hydroxybenzamide (39 mg, 0.2 mmol) in dry and degassed DMSO (2 mL) was heated under nitrogen atmosphere at 120 ^ for 20 h. Water (10 mL) is then added and product is extracted to EtOAc (3 x 10 mL). Combined organic layers were washed with water (3 x 10 mL) and brine (2 x 10 mL) and dried over Na₂S0₄. After evaporation of the solvent crude product is purified by chromatography to afford title compound: H NMR (CDCI₃, 500 MHz) δ 1 .63 (br s, 1 H), 2.33 (s, 3H), 2.37 (s, 3H), 3.02-3.09 (m, 8H), 6.52 (m, 1 H), 6.87 (m, 1 H), 7.04 (m, 1 H), 7.06-7.10 (m, 2H), 7.16 (m, 1 H), 7.39 (d, J= 7.8 Hz, 1 H); MS (ESI) m/z: 299 [MH]⁺.

Example 9: Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine hydrobromide

(vortioxetine HBr, VII.HBr)

To a solution of vortioxetine VII (1 .80 g, 6.03 mmol) in iPrOAc (20 mL) at room temperature 48% HBr (0.68 mL, 6.03 mmol) was slowly added. Obtained mixture was stirred at room temperature for 1 h, white precipitate was then filtered off, washed with acetone (2 x 20 mL), and dried to afford title compound VII.HBr as a white powder (2.15 g, 94% yield): H NMR (DMSO-d₆, 500 MHz) δ 2.23 (s, 3H), 2.32 (s, 3H), 3.15-3.27 (m, 8H), 6.40 (m, 1 H), 6.96 (m, 1 H), 7.08-7.17 (m, 3H), 7.24 (m, 1 H), 7.32 (d, J= 7.8 Hz, 1 H), 8.85 (br, 2H).

Reference Example 1 : Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine

(vortioxetine, VII)

Mixture of piperazine (1 .0 g, 1 1 .6 mmol), NaOtBu (1 .37 g, 13.8 mmol), Pddba₂ (40 mg, 0.07 mmol), and 1 ,3-bis(2,6-di-i-propylphenyl)imidazolium chloride (24 mg, 0,07 mmol) in dry and degassed toluene (10 mL) is stirred at room temperature for 1 h. (2,4-Dimethylphenyl)(2-iodophenyl)sulfane V (1 .32 g, 3.86 mmol) is then added, reaction mixture is heated to l OO'C and stirred for 24 h. After cooling to room temperature to the reaction mixture water (5 mL) and Celite (0.4 g) is added. After stirring for 20 min salts are filtered off, organic layer is separated, washed with brine (2 x 10 mL), dried over Na₂S0₄ and solvent is evaporated to afford crude product, which is then purified by chromatography to afford title compound as yellowish crystals: H NMR (CDCI₃, 500 MHz) δ 1 .63 (br s, 1 H), 2.33 (s, 3H), 2.37 (s, 3H),

Reference Example 2: Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine

(vortioxetine, VII)

Mixture of piperazine (1 .29 g, 15.0 mmol), NaOtBu (1 .77 g, 17.8 mmol), Pddba2 (52 mg, 0.09 mmol), and rac-BINAP (93 mg, 0,15 mmol) in dry and degassed toluene (10 mL) was stirred at room temperature for 1 h. (2,4-Dimethylphenyl)(2-iodophenyl)sulfane V (1 .70 g, 5.0 mmol) was then added, reaction mixture was heated to 100°C and stirred for 24 h. After cooled to room temperature to the reaction mixture water (5 mL) and Celite (0.4 g) were added. After stirring for 20 min salts were filtered off, organic layer was separated, washed with brine (2 x 10 mL), dried over Na₂S0₄ and solvent was evaporated to afford product as an orange oil (1 .41 g, 95% yield): H NMR (CDCI₃, 500 MHz) δ 1 .63 (br s, 1 H), 2.33 (s, 3H), 2.37 (s, 3H), 3.02-3.09 (m, 8H), 6.52 (m, 1 H), 6.87 (m, 1 H), 7.04 (m, 1 H), 7.06-7.10 (m, 2H), 7.16 (m, 1 H), 7.39 (d, J = 7.8 Hz, 1 H); MS (ESI) m/z: 299 [MH]⁺.

Comparative Example 1 : Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine

(vortioxetine, VII)

Mixture of (2,4-dimethylphenyl)(2-bromohenyl)sulfane V" (0.29 g, 1 .0 mmol), piperazine VI (0.13 g, 1 .5 mmol), K₃P0₃ (0.42 g, 2.0 mmol), Cul (19 mg, 0.1 mmol), and 2-phenylphenol (68 mg, 0.4 mmol) in dry and degassed DMSO (2 mL) was heated under nitrogen atmosphere at 120°C for 20 h. Vortioxetine VII was not formed.

Comparative Example 2: Preparation of 1 -(2-((2,4-dimethylphenyl)thio)phenyl)piperazine

(vortioxetine, VII)

Mixture of (2,4-dimethylphenyl)(2-bromophenyl)sulfane V (0.29 g, 1 .0 mmol), piperazine VI (0.13 g, 1 .5 mmol), K₃P0₃ (0.42 g, 2.0 mmol), Cul (19 mg, 0.1 mmol), and N,N-diethyl-2-hydroxybenzamide (39 mg, 0.2 mmol) in dry and degassed DMSO (2 mL) was heated under nitrogen atmosphere at 120 ^ for 20 h. Vortioxetine VII was not formed.


















Vojmir Urlep, President of the Lek Management Board,










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(WO2015139602) Sofosbuvir New Patent

(WO2015139602) 2'-SUBSTITUTED-2,2'-DEHYDRATED URIDINE OR 2'-SUBSTITUTED-2,2'-DEHYDRATED CYTIDINE COMPOUND AND PREPARATION METHOD AND USE THEREOF

ZHANG, Rongxia

A further object of the present invention to provide a method for preparing a compound of formula I.

The present invention provides a process for preparing a compound I 2'-deoxy-2'-fluoro-2'-substituted uridine or 2'-deoxy-2'-fluoro-cytidine using the following formula or 2'-deoxy-2'-substituted 2'-2'-substituted nitrile or uridine 2'-deoxy-2'-substituted-2'-carbonitrile The method of cytidine compound,

2'-deoxy-2'-fluoro-2'-methyl-uridine (IIIa) is the preparation of anti-hepatitis C drugs Sofosbuvir key intermediate.

Sofosbuvir developed by Gilead Science Company, FDA on December 6, 2013 Sofosbuvir formally approved for the treatment of chronic hepatitis C virus (HCV) infection. Sofosbuvir is first used to treat certain types of HCV infection without the use of interferon effective and safe drugs. Clinical trials have shown, sofosbuvir can achieve very high proportion of sustained virologic response (clinical cure). More revolutionary breakthrough that, sofosbuvir without joint peginterferon α situation is still very significant effect, such as sofosbuvir ribavirin genotype 2 and genotype 3 patients with previously untreated chronic hepatitis C continued virological response rate of 100%. Sofosbuvir is a prodrug is metabolized in vivo to 2'-deoxy-2'-fluoro-2'-methyl-uridine-5'-monophosphate.

Currently reported 2'-deoxy-2'-fluoro-2'-methyl uridine synthetic methods are as follows:

In the literature (Journal of Medicinal Chemistry, 2005,48,5504) in order cytidine as a raw material, first selectively protected 3 ', 5'-hydroxyl group, and then oxidizing the 2'-hydroxyl to a carbonyl group, and the reaction of methyllithium get the 2'-hydroxyl compound, and then removing the protective group, use benzoyl protected 3 ', 5'-hydroxyl group, and then reacted with DAST fluorinated compound, followed by hydrolysis and aminolysis reaction products, such as the following Reaction Scheme. The method of route length, the need to use expensive silicon ether protecting group molecule relatively poor economy; conducting methylation time will generate a non-methyl enantiomer beta bits.

In Patent (WO2005003147, WO2006031725A2, US20040158059) using 2'-fluoro-2'-methyl - ribose derivative with N- benzoyl cytosine for docking the reaction, then after the hydrolysis, aminolysis reaction to obtain the final product, As shown in the following reaction scheme. Raw material of the process is not readily available, synthetic steps cumbersome, expensive; the reaction product obtained contained docking base for the alpha position isomers, need purification removed to form waste.

SUMMARY OF THE INVENTION

The present inventors have designed and synthesized a compound of formula I as shown, the compound may be a fluorinated or nitrile reaction of 2'-deoxy-2'-fluoro-2'-get-substituted uridine or 2 under appropriate conditions' - 2'-deoxy-2'-fluoro-2'-deoxy-2'-substituted cytidine or nitrile uridine or 2'-substituted-2'-deoxy-2'-substituted-2'-cytidine nitrile compound; or a compound of formula I or a nitrile group by fluoro reaction, followed by deprotection reaction to give 2'-deoxy-2'-fluoro-2'-substituted uridine or 2'-deoxy-2'-fluoro--2 '- cytidine or 2'-substituted-2'-deoxy-2'-nitrile-substituted uridine or 2'-deoxy-2'-substituted-2'-cytidine compound nitrile group; or a compound of formula I through the opening cyclization reaction, and then through the group of fluoro or nitrile, and finally deprotection reaction to give 2'-deoxy-2'-fluoro-2'-substituted uridine or 2'-deoxy-2'-fluoro-2'-substituted Cellular glycoside or 2 'substituted-2'-deoxy-2'-carbonitrile 2'-deoxy-uridine or 2'-substituted-2'-cytidine compound nitrile group; or a compound of formula I through a ring-opening reaction, and then 2 '- hydroxyl forming a leaving group, and then after a nitrile group or a fluorinated reaction, the final deprotection reaction of 2'-deoxy-2'-fluoro-2'-substituted uridine or 2'-deoxy-2'- cytidine or 2'-fluoro-2'-substituted-2'-deoxy-2'-nitrile-substituted uridine or 2'-deoxy-2'-substituted-2'-cytidine nitrile compound.

It is therefore an object of the present invention is to provide a compound of the general formula I prepared 2'-deoxy-2'-fluoro-2'-substituted uridine or 2'-deoxy-2'-fluoro-2'-substituted cytidine or 2'-substituted-2'-deoxy-2'-carbonitrile uridine or 2'-deoxy-2'-substituted-2'-carbonitrile The method of cytidine compound.

Example 1:

The 2'-C- methyl uridine (18.4g, 0.07mol), N, N'- carbonyldiimidazole (216.2g, 0.10mol), sodium bicarbonate (8.4g, 0.10mol) was suspended N, N- two dimethylformamide (50ml), the temperature was raised to 130 ℃, reaction for 4 hours, cooled and filtered to remove inorganic salts, the filtrate was added ethyl acetate (200ml), analyze the material at room temperature, suction filtered, washed with ethyl acetate cooled to, drying to give a yellow solid (19.9g, yield: 83%).

Ia: ¹ H NMR (300 MHz, CD ₃ OD): [delta] 7.80 (d, 1H, J = 7.5 Hz), 6.05 (d, 1H, J = 7.5 Hz), 5.91 (s, 1H), 4.34 (d, 1H, J = 4.8Hz), 4.07 (m, 1H), 3.56 (m, 2H), 1.63 (s, 3H); ESI-MS m / z (M + 1) 241.

Example 2:

The compound of Example 1 Ia (0.24g, 1mmol)) was dissolved in 70% HF in pyridine was heated to 140 ~ 150 ℃, stirred for 3 hours, cooled and the solvent was removed under reduced pressure, the residue was added acetone, beating, and filtered to give solid (0.18g, yield: 70%).

IIIa: ¹ H NMR (300 MHz, DMSO-d ₆ ): [delta] 11.48 (s, 1H), 7.82 (d, 1H, J = 6.0 Hz), 6.00 (d, 1H, J = 15.6 Hz), 5.67 (m , 2H), 5.30 (s, 1H), 3.85 (m, 3H), 3.62 (s, 1H), 1.25 (d, 3H, J = 16.8Hz), ESI-MS m / z (M-1) 259.

Example 3:

Compound Ib (0.45g, 1mmol) was dissolved in a mixture of dichloromethane and pyridine, was added DAST (0.32g), stirred for 24 hours, added dichloromethane (20ml) was diluted with water (30ml × 2), dried over anhydrous dried over sodium sulfate, filtered and the solvent removed under reduced pressure to give the residue was subjected to column chromatography to give the product (0.36g, yield: 78%).

IIa: ¹ H NMR (400 MHz, CDCl ₃ and DMSO-d ₆ ): [delta] 7.99 (d, J = 7.6 Hz, 2H), 7.90 (d, J = 7.6 Hz, 2H), 7.34 ~ 7.61 (m, 7H ), 6.10 (brs, 1H), 5.64 (brs, 1H), 5.42 (d, J = 8.0Hz, 1H), 4.53-4.68 (m, 3H), 1.40 (d, J = 22.8Hz, 3H); ESI -MS m / z (M + 1) 469.

Example 4:

The compound of Example 3 IIa (0.47g, 1mmol) dissolved in 10% methanol solution of ammonia and stirred overnight, the solvent was removed under reduced pressure, and the residue was slurried in ethyl acetate, filtered to give a white solid (0.2g, yield : 77%).

IIIa: ¹ H NMR (300 MHz, DMSO-d ₆ ): [delta] 11.48 (s, 1H), 7.82 (d, 1H, J = 6.0 Hz), 6.00 (d, 1H, J = 15.6 Hz), 5.67 (m , 2H), 5.30 (s, 1H), 3.85 (m, 3H), 3.62 (s, 1H), 1.25 (d, 3H, J = 16.8Hz), ESI-MS m / z (M-1) 259.

Example 5:

Compound IVa (0.57g, 1mmol) was dissolved in dichloroethane (20ml) was added trifluoromethanesulfonic acid trimethylsilyl ester (1ml), was heated for 12 hours, cooled, and the reaction solution was concentrated dryness, added two dichloromethane (100ml) was dissolved, washed successively with water (50ml) and saturated brine (50ml), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated to dryness to give an oil which was purified by column chromatography to give a white solid (0.3g, yield : 67%).

Ib: ¹ H NMR (300 MHz, CDCl ₃ ): δ7.96-8.10 (m, 6H), 7.41-7.65 (m, 9H), 7.32 (d, 1H, J = 5.4 Hz), 6.09 (d, 1H, J = 5.4Hz), 5.79 (m, 2H), 4.67 (m, 1H), 4.48 (m, 2H), 1.81 (s, 3H); ESI-MS m / z (M-1) 447.

Example 6:

N The compound of Example 1 Ia (1.3g, 5.4mmol) dissolved in dry, N- dimethylformamide (10ml) was added p-toluenesulfonic acid monohydrate (1.12g, 5.9mmol) and 3,4- dihydropyran (1.28ml, 14.04mmol), The reaction was stirred for 5 hours at room temperature, water was added and the methylene chloride solution was separated, the organic layer was concentrated and purified by silica gel chromatography to give the product 1.3g.

Ic: ¹ H NMR (300 MHz, CDCl ₃ ): [delta] 7.29 (m, 1H), 6.08 (m, 1H), 5.61 (m, 1H), 4.33-4.72 (m, 4H), 3.37-3.90 (m, 6H), 1.43-1.82 (m, 12H), 1.25 (s, 3H); ESI-MS m / z (M + 1) 427.

Example 7:

The solvent was removed, the residue was purified compound of Example 6 Ic (0.43g, 1mmol) was dissolved in 70% HF in pyridine was heated to 100 ~ 120 ℃, stirred for 5 hours, cooled, reduced pressure was purified through silica gel column to give a solid ( 0.18g, yield: 72%).

IIIa: ¹ H NMR (300 MHz, DMSO-d ₆ ): [delta] 11.48 (s, 1H), 7.82 (d, 1H, J = 6.0 Hz), 6.00 (d, 1H, J = 15.6 Hz), 5.67 (m , 2H), 5.30 (s, 1H), 3.85 (m, 3H), 3.62 (s, 1H), 1.25 (d, 3H, J = 16.8Hz), ESI-MS m / z (M-1) 259.

Example 8:

The compound of Example 6 Ic (50mg, 0.122mmol) was dissolved in methanol (1ml) was added 1N sodium hydroxide solution (0.2ml), stirred at room temperature overnight, water was added and the methylene chloride solution was separated, the organic layer was concentrated after purified by column chromatography to give the product (45mg, yield: 87%).

VA: ¹ H NMR (300 MHz, CDCl ₃ ): [delta] 7.89 (d, 1H, J = 4.5Hz), 6.01 (s, 1H), 5.95 (d, 1H, J = 4.5Hz), 5.65 (m, 2H ), 4.73 (m, 3H), 4.59 (m, 1H), 3.52-4.30 (m, 4H), 1.56-1.80 (m, 12H), 1.32 (s, 3H); ESI-MS m / z (M + 35) 461.

Example 9:

The mixture of Example 8 Compound Va (0.43g, 1mmol) was dissolved in dichloromethane and pyridine, was added DAST (0.32g), stirred for 24 hours, added dichloromethane (20ml) was diluted with water (30ml × 2) and washed , dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain compound IIb. Compound IIb is dissolved in methanol (10ml) was added p-toluenesulfonic acid (200mg), stirred for 6 hours at room temperature, the methanol was removed under reduced pressure, silica gel column chromatography to give the product IIIa (180mg, yield: 75%).

IIIa: ¹ H NMR (300 MHz, DMSO-d ₆ ): [delta] 11.48 (s, 1H), 7.82 (d, 1H, J = 6.0 Hz), 6.00 (d, 1H, J = 15.6 Hz), 5.67 (m , 2H), 5.30 (s, 1H), 3.85 (m, 3H), 3.62 (s, 1H), 1.25 (d, 3H, J = 16.8Hz), ESI-MS m / z (M-1) 259.

Example 10:

The 2'-C- methyl uridine (0.2g, 0.8mmol) was dissolved in N, N- dimethylformamide (4ml) was added N, N'- carbonyldiimidazole (0.194g, 1.2mmol) and sodium bicarbonate (55mg, 0.66mmol), was heated to 130 ℃, stirred for 4 hours, cooled and the solvent was removed under reduced pressure, and the residue was dissolved in 70% HF in pyridine was heated to 140 ~ 150 ℃, stirred for 3 hours, cooled, The solvent was removed under reduced pressure, the residue was added to acetone and filtered to obtain a solid IIIa (0.12g, yield: 60%).

Example 11:

The 2'-C- methyl uridine (0.2g, 0.8mmol) was dissolved in N, N- dimethylformamide (4ml) was added diphenyl carbonate (0.256g, 1.2mmol) and sodium bicarbonate ( 55mg, 0.66mmol), was heated to 150 ℃, stirred for 6 hours, cooled and the solvent was removed under reduced pressure, and the residue was dissolved in 70% HF in pyridine was heated to 140 ~ 150 ℃, stirred for 3 hours, cooled and the solvent was removed under reduced pressure The residue was added to acetone and filtered to obtain a solid IIIa (0.13g, yield: 65%).

Example 12:

Under nitrogen, the compound of Example 9 Example Va (4.26g, 10mmol) was dissolved in dry tetrahydrofuran (100ml) was added triethylamine (6g, 60mmol), cooled to -78 ℃, was added trifluoromethanesulfonic anhydride (4.23g , 15mmol), stirred for 1 hour, the reaction system was added saturated ammonium chloride solution, extracted three times with methylene chloride, organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and the residue was subjected to silica gel column chromatography to give the product Vb ( 4g, yield: 72%). ESI-MS m / z (M-1) 557.

Compound Vb (4g) was dissolved in dry tetrahydrofuran, was added tetrabutylammonium fluoride (1.87g, 7.1mmol), warmed to reflux, cooled to room temperature after heating for 1 hour, water was added to the reaction system, and extracted with methylene chloride three times, the combined organic phase was dried over anhydrous sodium sulfate, concentrated, and the residue was subjected to silica gel column chromatography to give the product IIb (2.7g, yield: 88%). ESI-MS m / z (M-1) 427.

Compound IIb (2.7g) was dissolved in methanol (20ml) was added 3M hydrochloric acid (10ml), 50 ℃ stirred for 8 hours, and concentrated to give a solid, was added acetonitrile, beating, and filtered to give the product IIIa (1g, yield: 61%).

IIIa: ¹ H NMR (300 MHz, DMSO-d ₆ ): [delta] 11.48 (s, 1H), 7.82 (d, 1H, J = 6.0 Hz), 6.00 (d, 1H, J = 15.6 Hz), 5.67 (m , 2H), 5.30 (s, 1H), 3.85 (m, 3H), 3.62 (s, 1H), 1.25 (d, 3H, J = 16.8Hz), ESI-MS m / z (M-1) 259.

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Pregabalin

15 16 (S)-Pregabalin

Example 7: Preparation of (S) Pregabalin from compound 19

1Og of compound 19 is dissolved in 440 ml 6 N HCl, and the solution is warmed to 125°C for 15 hours. After cooling, the mixture is diluted with water, and extracted three times with dichloromethane, then the aqueous phase is evaporated. After drying under high vacuum, the (S)-Pregabalin hydrochloride is obtained as crystals. (S)-Pregabalin is further resolved by dissolving (S)-Pregabalin hydrochloride in isobutanol, and then adding triethyl amine. The mixture is stirred for 45 minutes, and the product is filtered, washed with isobutanol.

http://www.google.com/patents/WO2006110783A2?cl=en

Publication number	WO2006110783 A2
Publication type	Application
Application number	PCT/US2006/013565
Publication date	Oct 19, 2006
Filing date	Apr 11, 2006
Priority date	Apr 11, 2005
Also published as	CA2603215A1, 4 More »
Inventors	Asher Maymon, Vinod Kumar Kansal, Lilach Hedvati
Applicant	Teva Pharma, Asher Maymon, Vinod Kumar Kansal, Lilach Hedvati
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External Links: Patentscope, Espacenet Citing Patent Filing date Publication date Applicant Title WO2008007145A2 * Jul 12, 2007 Jan 17, 2008 Generics Uk Ltd Process of preparing a gamma-amino acid WO2008117305A2 * Mar 3, 2008 Oct 2, 2008 Venkata Siva Kumar Bobba A novel process for preparing pregabalin and its acid addition salts WO2009010554A1 * Jul 17, 2008 Jan 22, 2009 Esteve Labor Dr Process for the enantioselective preparation of pregabalin WO2009022839A2 * Aug 11, 2008 Feb 19, 2009 Korea Advanced Inst Sci & Tech Novel method for preparing pregabalin WO2009080365A1 * Dec 18, 2008 Jul 2, 2009 Synthon Bv Pregabalin salts WO2009081208A1 * Dec 19, 2008 Jul 2, 2009 Generics Uk Ltd Processes to pregabalin WO2009087650A2 * Oct 14, 2008 Jul 16, 2009 Sundeep Aurora A novel process for synthesis of pregabalin from substituted cyclopropane intermediate and a process for enzymatic resolution of racemic pregabalin WO2009141362A2 * May 19, 2009 Nov 26, 2009 Sandoz Ag Process for the stereoselective enzymatic hydrolysis of 5-methyl-3-nitromethyl-hexanoic acid ester WO2009147434A1 * Jun 3, 2009 Dec 10, 2009 Generics [Uk] Limited A novel and efficient method for the synthesis of an amino acid WO2009149928A1 * Jun 10, 2009 Dec 17, 2009 Synthon B.V. Processes for making pregabalin and intermediates therefor WO2014005494A1 * Jun 28, 2013 Jan 9, 2014 Sunshine Lake Pharma Co., Ltd. Method of preparing lactam compound EP2017273A1 * Jul 18, 2007 Jan 21, 2009 Laboratorios del Dr. Esteve S.A. Process for the enantioselective preparation of pregabalin US7586005 Oct 28, 2008 Sep 8, 2009 Teva Pharmaceutical Industries Ltd. Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US7619112 Aug 14, 2007 Nov 17, 2009 Teva Pharmaceutical Industries Ltd. Optical resolution of 3-carbamoylmethyl-5-methyl hexanoic acid US7678938 Aug 14, 2007 Mar 16, 2010 Teva Pharmaceutical Industries Ltd. Optical resolution of 3-carbamoylmethyl-5-methyl hexanoic acid US7763749 May 10, 2006 Jul 27, 2010 Teva Pharmaceutical Industries Ltd. Method for the preparation of Pregabalin and salts thereof US7851651 Oct 28, 2008 Dec 14, 2010 Teva Pharmaceutical Industries Ltd. Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US7923575 Oct 19, 2009 Apr 12, 2011 Teva Pharmaceutical Industries Limited Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US7960583 Oct 28, 2008 Jun 14, 2011 Teva Pharmaceutical Industries Ltd. Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US7973196 Aug 30, 2010 Jul 5, 2011 Teva Pharmaceutical Industries Ltd. Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US8097754 Mar 24, 2008 Jan 17, 2012 Teva Pharmaceutical Industries Ltd. Synthesis of (S)-(+)-3-(aminomethyl)-5-methyl hexanoic acid US8212071 Nov 4, 2008 Jul 3, 2012 Teva Pharmaceutical Industries Ltd. Asymmetric synthesis of (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid US8546112 May 19, 2009 Oct 1, 2013 Sandoz Ag Process for the stereoselective enzymatic hydrolysis of 5-methyl-3-nitromethyl-hexanoic acid ester