ethyl (2R)-5-oxopyrrolidine-2-carboxylate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 9.1 Reaction of 1.0 g of ethyl(R)-5-oxopyrrolidine-2-carboxylate, 949.8 μl of benzyl chloroformate, 6.9 ml of bis(trimethylsilyl)lithium amide (in THF) in 25 ml of THF under standard conditions and work-up gives 730 mg of ethyl(R)-5-oxo-N-benzyloxycarbonylpyrrolidine-2-carboxylate (“17”).

反応条件: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of (R)-ethyl 5-oxo-pyrrolidine-2-carboxylate (2760 mg, 17.56 mmol), bromobenzene (2.034 ml, 3030 mg, 19.32 mmol), Pd2(dba)3 (402 mg, 0.439 mmol), Cs2CO3 (8580 mg, 26.3 mmol), and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos, 254 mg, 0.439 mmol) in 70 ml of dioxane was stirred at 100° C. for 6 h under nitrogen atmosphere. Due to only partial reaction after this time additional Pd2(dba)3 (402 mg, 0.439 mmol), Cs2CO3 (2860 mg, 8.77 mmol) and Xantphos (254 mg, 0.439 mmol) were added and stiffing at 100° C. was continued for additional 6 h. The reaction mixture was then filtered via a short celite column, the solvent was removed under reduced pressure, and the remaining residue was taken up in ethyl acetate, washed successively with an aq. sat. NaHCO3 solution and an aq. citric acid solution (each 3×), then with water and brine. The organic layer was dried over Na2SO4, the solvent evaporated under reduced pressure, and the obtained residue purified by column chromatography on silica gel using dichloromethane to give (R)-ethyl 5-oxo-1-phenylpyrrolidine-2-carboxylate as a brown oil (715 mg, 3.07 mmol; yield: 17%; ESI-MS [M+H]+=234.1). Saponification to the corresponding carboxylate was achieved by stirring at room temperature overnight in a solution of 4 ml ethanol and 1.84 ml 2N NaOH (aq). Subsequent evaporation of the solvent followed by addition of water, extraction with MTBE (3×), acidification of the aqueous layer to pH 3 using concentrated HCl, extraction with dichloromethane (3×), washing the combined organic layers with brine, drying over MgSO4 and removing the solvent under reduced pressure yielded the title compound as a pale brown powder (0.5 g; yield: 79%). were added stiffing at 100° C. was continued for additional 6 h The reaction mixture was then filtered via a short celite column the solvent was removed under reduced pressure washed successively with an aq. sat. NaHCO3 solution The organic layer was dried over Na2SO4 the solvent evaporated under reduced pressure the obtained residue purified by column chromatography on silica gel

反応条件: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of (R)-ethyl 5-oxo-pyrrolidine-2-carboxylate (2760 mg, 17.56 mmol), bromobenzene (2.034 ml, 3030 mg, 19.32 mmol), Pd2(dba)3 (402 mg, 0.439 mmol), Cs2CO3 (8580 mg, 26.3 mmol), and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos, 254 mg, 0.439 mmol) in 70 ml of dioxane was stirred at 100° C. for 6 h under nitrogen atmosphere. Due to only partial reaction after this time additional Pd2(dba)3 (402 mg, 0.439 mmol), Cs2CO3 (2860 mg, 8.77 mmol) and Xantphos (254 mg, 0.439 mmol) were added and stiffing at 100° C. was continued for additional 6 h. The reaction mixture was then filtered via a short celite column, the solvent was removed under reduced pressure, and the remaining residue was taken up in ethyl acetate, washed successively with an aq. sat. NaHCO3 solution and an aq. citric acid solution (each 3×), then with water and brine. The organic layer was dried over Na2SO4, the solvent evaporated under reduced pressure, and the obtained residue purified by column chromatography on silica gel using dichloromethane to give (R)-ethyl 5-oxo-1-phenylpyrrolidine-2-carboxylate as a brown oil (715 mg, 3.07 mmol; yield: 17%; ESI-MS [M+H]+=234.1). Saponification to the corresponding carboxylate was achieved by stirring at room temperature overnight in a solution of 4 ml ethanol and 1.84 ml 2N NaOH (aq). Subsequent evaporation of the solvent followed by addition of water, extraction with MTBE (3×), acidification of the aqueous layer to pH 3 using concentrated HCl, extraction with dichloromethane (3×), washing the combined organic layers with brine, drying over MgSO4 and removing the solvent under reduced pressure yielded the title compound as a pale brown powder (0.5 g; yield: 79%). were added stiffing at 100° C. was continued for additional 6 h The reaction mixture was then filtered via a short celite column the solvent was removed under reduced pressure washed successively with an aq. sat. NaHCO3 solution The organic layer was dried over Na2SO4 the solvent evaporated under reduced pressure the obtained residue purified by column chromatography on silica gel

反応条件: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To the solution of (R)-ethyl 5-oxo-pyrrolidine-2-carboxylate (D-pyroglutamic acid ethyl ester; 99% pure; 1403 mg, 8.84 mmol) in 20 ml of DMF 1-(bromomethyl)-2-(trifluoromethyl)benzene (96% pure; 2200 mg, 8.84 mmol), K2CO3 (3660 mg, 26.5 mmol) and a small amount of each KI and 18-crown-6 were added, and the mixture was heated at 80° C. for 6 h. Subsequently the mixture was poured into water and extracted three times with MTBE. The organic layer was washed with brine, dried over MgSO4 and the solvent removed under reduced pressure. Chromatography on silica gel using dichloromethane and dichloromethane/MeOH (99:1) resulted in (R)-5-oxo-1-(2-trifluoromethyl-benzyl)-pyrrolidine-2-carboxylic acid ethyl ester (410 mg, ESI-MS [M+H]+=316.1; yield: 12%), which was hydrolyzed to the corresponding carboxylate by stiffing overnight at room temperature in a solution of 15 ml ethanol and 1.56 mL 2N NaOH (aq). Evaporation of the solvent, followed by addition of water to the residue, extraction with ethyl acetate, subsequent acidification of the aqueous layer to pH 3 using concentrated HCl, extraction with dichloromethane, drying of the combined organic layers with MgSO4 and removal of the solvent under reduced pressure led to the desired product as a white foam. extracted three times with MTBE The organic layer was washed with brine dried over MgSO4 the solvent removed under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (R)-5-oxopyrrolidine-2-carboxylic acid (10 g, 69.84 mmol; available from Aldrich#422614) in EtOH (100 ml) cooled at −5° C., thionyl chloride (10 ml, 139.68 mmol) was added and the resulting mixture was stirred at RT for 3 hrs. Solvents were evaporated in vacuo and the resulting residue was taken up with EtOAc (350 ml), washed with water/TEA (40/12 ml), then with water (40 ml). Collected organics were dried over Na2SO4 and evaporated to afford a residue that was loaded on a SNAP-Si cartridge (50 g) and eluted with a mixture DCM/EtOAc from 90/10 to 50/50. Collected fractions after solvent evaporation afforded a first batch of title compound (D23) (6.4 g). The aqueous were saturated with NaCl and extracted with EtOAc (400 ml). The organic was washed with water (20 ml) dried over Na2SO4 and evaporated in vacuo to afford a second batch of title compound (D23) (3.7 g). Solvents were evaporated in vacuo washed with water/TEA (40/12 ml) Collected organics were dried over Na2SO4 evaporated to afford a residue that eluted with a mixture DCM/EtOAc from 90/10 to 50/50 Collected fractions after solvent evaporation

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (R)-5-oxopyrrolidine-2-carboxylic acid (10 g, 69.84 mmol; available from Aldrich#422614) in EtOH (100 ml) cooled at −5° C., thionyl chloride (10 ml, 139.68 mmol) was added and the resulting mixture was stirred at RT for 3 hrs. Solvents were evaporated in vacuo and the resulting residue was taken up with EtOAc (350 ml), washed with water/TEA (40/12 ml), then with water (40 ml). Collected organics were dried over Na2SO4 and evaporated to afford a residue that was loaded on a SNAP-Si cartridge (50 g) and eluted with a mixture DCM/EtOAc from 90/10 to 50/50. Collected fractions after solvent evaporation afforded a first batch of title compound (D23) (6.4 g). The aqueous were saturated with NaCl and extracted with EtOAc (400 ml). The organic was washed with water (20 ml) dried over Na2SO4 and evaporated in vacuo to afford a second batch of title compound (D23) (3.7 g). Solvents were evaporated in vacuo washed with water/TEA (40/12 ml) Collected organics were dried over Na2SO4 evaporated to afford a residue that eluted with a mixture DCM/EtOAc from 90/10 to 50/50 Collected fractions after solvent evaporation

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of (R)-ethyl 5-oxopyrrolidin-2-carboxylate (Aldrich, 3 g, 19 mmol) and sodium borohydride (1.89 g, 50 mmol) in tetrahydrofuran (30 mL) at 50° C. was added dropwise for 30 min methanol (10 mL). The reaction was then continued for an additional 15 min and cooled to room temperature. The mixture was treated with 1N HCl to pH=3 and concentrated under reduced pressure. The residue was triturated with anhydrous methanol and the solid was filtered off and washed with methanol. The filtrate and washings were combined and concentrated under reduced pressure. The concentrate was then triturated with anhydrous tetrahydrofuran and filtered. The filtrate was concentrated under reduced pressure and the concentrate was dissolved in anhydrous CH2Cl2 (20 mL). p-Toluenesulfonyl chloride (3.64 g, 19 mmol) was added, the mixture was cooled to 0° C. and triethylamine (2.66 mL, 19 mmol) was added dropwise. The reaction mixture was allowed to warm to room temperature and stirred for 12 h. The mixture was then washed with water, brine, dried with anhydrous MgSO4 and concentrated under reduced pressure. The residue was chromatographed (SiO2, ethyl acetate-ethanol 9:1) to afford 3.5 g of the title compound. 1H NMR (300 MHz, DMSO-d6) δ 1.62 (m 1H), 2.06 (m, 3H), 2.42 (s, 3H), 3.71 (m, 1H), 3.87 (dd, J=10 Hz, 4 Hz, 1H), 3.97 (dd, J=10 Hz, 4 Hz, 1H), 7.49 (d, J=9 Hz, 2H), 7.75 (broad s, 1H), 7.82 (d, J=9 Hz, 2H); MS (DCI/NH3) m/z 270 (M+H)+, 287 (M+NH4)+. concentrated under reduced pressure The residue was triturated with anhydrous methanol the solid was filtered off washed with methanol concentrated under reduced pressure The concentrate was then triturated with anhydrous tetrahydrofuran filtered The filtrate was concentrated under reduced pressure the concentrate was dissolved in anhydrous CH2Cl2 (20 mL) the mixture was cooled to 0° C. to warm to room temperature The mixture was then washed with water, brine dried with anhydrous MgSO4 concentrated under reduced pressure The residue was chromatographed (SiO2, ethyl acetate-ethanol 9:1)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: D-pyroglutamic acid ethyl ester (0.200 g, 1.27 mmol) was dissolved in dioxane (5 ml) and treated with tris(dibenzylideneacetone)dipalladium (0) (0.058 g, 0.06 mmol), bromobenzene (0.351 ml, 1.53 mmol), cesium carbonate (0.621 g, 1.91 mmol) and Xantphos™ (0.110 g, 0.19 mmol). The resulting mixture was heated at reflux overnight and then allowed to cool to room temperature. The mixture was diluted with methanol and filtered. The filtrate was evaporated in vacuo and then partitioned between dichloromethane and saturated aqueous sodium hydrogen carbonate. The aqueous layer was extracted with more dichloromethane (3 aliquots) and then the combined organic layers were washed with brine and dried over magnesium sulphate. Evaporation of the solvent gave a bright yellow residue which was purified by flash silica column chromatography, eluting with a gradient of 0-50% ethyl acetate in hexane, to give methyl 5-oxo-1-phenylprolinate (0.078 g) as a yellow oil. This was used in the next step without further purification. The resulting mixture was heated at reflux overnight filtered The filtrate was evaporated in vacuo partitioned between dichloromethane and saturated aqueous sodium hydrogen carbonate The aqueous layer was extracted with more dichloromethane (3 aliquots) the combined organic layers were washed with brine dried over magnesium sulphate Evaporation of the solvent gave a bright yellow residue which was purified by flash silica column chromatography eluting with a gradient of 0-50% ethyl acetate in hexane

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: D-pyroglutamic acid ethyl ester (4.0 g, 25.5 mmol) was dissolved in tetrahydrofuran (25 ml) and cooled to 0° C. Methyl iodide (1.66 ml, 26.7 mmol) was added and stirring continued for 10 minutes under argon at 0° C. Sodium hydride (60% in oil, 1.6 g, 26.7 mmol) was then added portionwise (allowing each portion to react). After addition of all the sodium hydride the mixture was allowed to warm to room temperature and stirred overnight under argon. The mixture was then treated with saturated aqueous ammonium chloride solution (˜15 ml) and stirred for 4 hrs. The organic layer was separated and the aqueous layer was extracted with more dichloromethane. The combined organic layers were dried over magnesium sulphate and then concentrated to a dark oil. This was purified by flash silica column chromatography, eluting with a 0-75% gradient of ethyl acetate in hexane, to give ethyl 1-methyl-5-oxoprolinate as a colourless oil (0.27 g) which was used in the next step without further purification. to react) to warm to room temperature stirred overnight under argon stirred for 4 hrs The organic layer was separated the aqueous layer was extracted with more dichloromethane The combined organic layers were dried over magnesium sulphate concentrated to a dark oil This was purified by flash silica column chromatography eluting with a 0-75% gradient of ethyl acetate in hexane

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: D-pyroglutamic acid ethyl ester (4.17 g, 26.53 mmol) was dissolved in tetrahydrofuran (30 ml) and ethyl iodide (2.23 ml, 27.86 mmol) was added to give a pale yellow solution. This was cooled to 0° C. and sodium hydride (60% in oil, 1.11 g, 27.86 mmol) was added portionwise. After addition of all the sodium hydride the mixture was stirred at 0° C. for a further 20 minutes until most of the bubbling had stopped. The mixture was then warmed to room temperature and stirred overnight under argon. The mixture was then treated with saturated aqueous ammonium chloride solution (˜5 ml). The organic layer was separated and the aqueous layer was extracted with more dichloromethane (3×20 ml). The combined organic layers were dried by passing through a phase separator and then concentrated to a green/brown oil (3.2 g). This was purified by automated flash silica column chromatography (Biotage SP4), eluting with a 0-100% gradient of ethyl acetate in hexane, to give ethyl 1-ethyl-5-oxoprolinate as a yellow oil (1.33 g) which was used in the next step without further purification. to give a pale yellow solution The mixture was then warmed to room temperature stirred overnight under argon The organic layer was separated the aqueous layer was extracted with more dichloromethane (3×20 ml) The combined organic layers were dried concentrated to a green/brown oil (3.2 g) This was purified by automated flash silica column chromatography (Biotage SP4) eluting with a 0-100% gradient of ethyl acetate in hexane

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: D-pyroglutamic acid ethyl ester (4.17 g, 26.53 mmol) was dissolved in tetrahydrofuran (30 ml) and ethyl iodide (2.23 ml, 27.86 mmol) was added to give a pale yellow solution. This was cooled to 0° C. and sodium hydride (60% in oil, 1.11 g, 27.86 mmol) was added portionwise. After addition of all the sodium hydride the mixture was stirred at 0° C. for a further 20 minutes until most of the bubbling had stopped. The mixture was then warmed to room temperature and stirred overnight under argon. The mixture was then treated with saturated aqueous ammonium chloride solution (˜5 ml). The organic layer was separated and the aqueous layer was extracted with more dichloromethane (3×20 ml). The combined organic layers were dried by passing through a phase separator and then concentrated to a green/brown oil (3.2 g). This was purified by automated flash silica column chromatography (Biotage SP4), eluting with a 0-100% gradient of ethyl acetate in hexane, to give ethyl 1-ethyl-5-oxoprolinate as a yellow oil (1.33 g) which was used in the next step without further purification. to give a pale yellow solution The mixture was then warmed to room temperature stirred overnight under argon The organic layer was separated the aqueous layer was extracted with more dichloromethane (3×20 ml) The combined organic layers were dried concentrated to a green/brown oil (3.2 g) This was purified by automated flash silica column chromatography (Biotage SP4) eluting with a 0-100% gradient of ethyl acetate in hexane

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of D-pyroglutamic acid (compound I-A, 20.4 g, 0.16 mol) in 100 mL of EtOH, 1.2 mL of conc. sulfuric acid was added. The mixture was heated under reflux overnight. Solvent was removed under reduced pressure to give (R)-ethyl 5-oxopyrrolidine-2-carboxylate (compound II-AA). The mixture was heated under reflux overnight Solvent was removed under reduced pressure