tert-butyl N-(3-oxo-1,2-oxazolidin-4-yl)carbamate

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: As described in Example 4, Step A, (3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.30 g) was alkylated with 2,2-difluoroethyl trifluoromethanesulfonate (0.35 g). to afford the title product as a white solid (138 mg); 1H-NMR (CDCl3, 400 MHz): 6.05 (tt, 1H), 5.10 (m, 1H), 4.90 (m, 1H), 4.35 (dt, 2H), 4.20 (dd, 1H), 1.50 (s, 9H); along with the O-alkylated product (179 mg): 1H-NMR (CDCl3, 400 MHz): 5.95 (tt, 1H), 4.80 (m, 1H), 4.60 (m, 1H), 3.80-4.10 (m, 3H), 1.50 (s, 9H).

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: As described in Example 4, Step A, (3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.30 g) was alkylated with 2,2-difluoroethyl trifluoromethanesulfonate (0.35 g). to afford the title product as a white solid (138 mg); 1H-NMR (CDCl3, 400 MHz): 6.05 (tt, 1H), 5.10 (m, 1H), 4.90 (m, 1H), 4.35 (dt, 2H), 4.20 (dd, 1H), 1.50 (s, 9H); along with the O-alkylated product (179 mg): 1H-NMR (CDCl3, 400 MHz): 5.95 (tt, 1H), 4.80 (m, 1H), 4.60 (m, 1H), 3.80-4.10 (m, 3H), 1.50 (s, 9H).

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of triphenylphosphine (0.79 g) in THF (22 ml) was cooled under argon to −10° C. Diethylazodicarboxylate (DEAD, 1.57 g) was added dropwise then thietan-3-ol (0.4 g) and (3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.27 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557). The reaction mixture was stirred at room temperature for 24 hours then the solvent was removed in vacuo. The crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford the title product as a white solid (51 mg). 1H-NMR (CDCl3, 400 MHz): 5.45 (q, 1H), 5.05 (m, 1H), 4.90 (m, 1H), 4.50 (t, 1H), 4.10 (dd, 1H), 3.55 (m, 2H), 3.40 (m, 2H), 1.50 (s, 9H). the solvent was removed in vacuo The crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.2 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in acetonitrile (20 ml), then potassium carbonate (0.69 g), potassium iodide (0.175 g) and 2-bromoethanol (0.137 g) were added. The reaction was stirred at room temperature for 1 hour. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water, brine and then dried over sodium sulphate. The solvent was removed in vacuo and the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford ((R)-2-(2-hydroxyethyl)-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester as a yellow solid. LCMS (method A) 1.05 min, MH+ 259; 1H-NMR (CDCl3, 400 MHz): 5.55 (br s, 1H), 4.65 (m, 2H), 4.10 (t, 1H), 3.80 (m, 1H), 3.20 (br s, 1H), 1.50 (s, 9H), 1.20 (m, 3H). The reaction mixture was partitioned between ethyl acetate and water The organic layer was washed with water, brine dried over sodium sulphate The solvent was removed in vacuo the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.2 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in acetonitrile (20 ml), then potassium carbonate (0.69 g), potassium iodide (0.175 g) and 2-bromoethanol (0.137 g) were added. The reaction was stirred at room temperature for 1 hour. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water, brine and then dried over sodium sulphate. The solvent was removed in vacuo and the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford ((R)-2-(2-hydroxyethyl)-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester as a yellow solid. LCMS (method A) 1.05 min, MH+ 259; 1H-NMR (CDCl3, 400 MHz): 5.55 (br s, 1H), 4.65 (m, 2H), 4.10 (t, 1H), 3.80 (m, 1H), 3.20 (br s, 1H), 1.50 (s, 9H), 1.20 (m, 3H). The reaction mixture was partitioned between ethyl acetate and water The organic layer was washed with water, brine dried over sodium sulphate The solvent was removed in vacuo the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.2 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in acetonitrile (20 ml) then potassium carbonate (0.69 g), potassium iodide (0.175 g) and bromoethane (0.13 g) were added. The reaction was heated under microwave irradiation for 1 hour at 140° C. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water, brine and then dried over sodium sulphate. The solvent was removed in vacuo and the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford ((R)-2-ethyl-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester as a yellow solid. LCMS (method A) 1.29 min, MH+(-BOC) 131; 1H-NMR (CDCl3, 400 MHz): 5.10 (m, 1H), 4.75 (m, 1H), 4.55 (m, 1H), 3.95 (m, 1H), 3.60 (m, 2H), 1.50 (s, 9H), 1.20 (m, 3H). The reaction mixture was partitioned between ethyl acetate and water The organic layer was washed with water, brine dried over sodium sulphate The solvent was removed in vacuo the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (1.01 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in dimethylformamide (5 ml), the solution was cooled to 0° C. and 616 mg of potassium t-butoxide was added portionwise. The reaction mixture was stirred at 0° C. for 1 hour then 710 mg methylene iodide was added and the reaction mixture was stirred for 3 hours at room temperature. The reaction mixture was poured into water and extracted with diethyl ether. The organic phase was then washed several times with water, dried over sodium sulphate and the solvent removed in vacuo. Crude ((R)-2-methyl-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (140 mg) was obtained as a white solid. LCMS (method A) 1.11 min, MH+ 217; 1H-NMR (CDCl3, 400 MHz): 5.20 (m, 1H), 4.70 (m, 1H), 4.55 (m, 1H), 4.00 (dd, 1H), 3.20 (s, 3H), 1.40 (s, 9H). the reaction mixture was stirred for 3 hours at room temperature extracted with diethyl ether The organic phase was then washed several times with water dried over sodium sulphate the solvent removed in vacuo

反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (1.01 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in dimethylformamide (5 ml), the solution was cooled to 0° C. and 616 mg of potassium t-butoxide was added portionwise. The reaction mixture was stirred at 0° C. for 1 hour then 710 mg methylene iodide was added and the reaction mixture was stirred for 3 hours at room temperature. The reaction mixture was poured into water and extracted with diethyl ether. The organic phase was then washed several times with water, dried over sodium sulphate and the solvent removed in vacuo. Crude ((R)-2-methyl-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (140 mg) was obtained as a white solid. LCMS (method A) 1.11 min, MH+ 217; 1H-NMR (CDCl3, 400 MHz): 5.20 (m, 1H), 4.70 (m, 1H), 4.55 (m, 1H), 4.00 (dd, 1H), 3.20 (s, 3H), 1.40 (s, 9H). the reaction mixture was stirred for 3 hours at room temperature extracted with diethyl ether The organic phase was then washed several times with water dried over sodium sulphate the solvent removed in vacuo

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: As described in Example 4, Step A, (3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.30 g) was alkylated with 2,2-difluoroethyl trifluoromethanesulfonate (0.35 g). to afford the title product as a white solid (138 mg); 1H-NMR (CDCl3, 400 MHz): 6.05 (tt, 1H), 5.10 (m, 1H), 4.90 (m, 1H), 4.35 (dt, 2H), 4.20 (dd, 1H), 1.50 (s, 9H); along with the O-alkylated product (179 mg): 1H-NMR (CDCl3, 400 MHz): 5.95 (tt, 1H), 4.80 (m, 1H), 4.60 (m, 1H), 3.80-4.10 (m, 3H), 1.50 (s, 9H).

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of triphenylphosphine (0.79 g) in THF (22 ml) was cooled under argon to −10° C. Diethylazodicarboxylate (DEAD, 1.57 g) was added dropwise then thietan-3-ol (0.4 g) and (3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.27 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557). The reaction mixture was stirred at room temperature for 24 hours then the solvent was removed in vacuo. The crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford the title product as a white solid (51 mg). 1H-NMR (CDCl3, 400 MHz): 5.45 (q, 1H), 5.05 (m, 1H), 4.90 (m, 1H), 4.50 (t, 1H), 4.10 (dd, 1H), 3.55 (m, 2H), 3.40 (m, 2H), 1.50 (s, 9H). the solvent was removed in vacuo The crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.2 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in acetonitrile (20 ml), then potassium carbonate (0.69 g), potassium iodide (0.175 g) and 2-bromoethanol (0.137 g) were added. The reaction was stirred at room temperature for 1 hour. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water, brine and then dried over sodium sulphate. The solvent was removed in vacuo and the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford ((R)-2-(2-hydroxyethyl)-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester as a yellow solid. LCMS (method A) 1.05 min, MH+ 259; 1H-NMR (CDCl3, 400 MHz): 5.55 (br s, 1H), 4.65 (m, 2H), 4.10 (t, 1H), 3.80 (m, 1H), 3.20 (br s, 1H), 1.50 (s, 9H), 1.20 (m, 3H). The reaction mixture was partitioned between ethyl acetate and water The organic layer was washed with water, brine dried over sodium sulphate The solvent was removed in vacuo the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)

反应条件: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (3-Oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester (0.2 g, prepared from (D)-cycloserine as described in Chem. Pharm. Bull. 2002, 50(4) 554-557) was dissolved in acetonitrile (20 ml) then potassium carbonate (0.69 g), potassium iodide (0.175 g) and bromoethane (0.13 g) were added. The reaction was heated under microwave irradiation for 1 hour at 140° C. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was washed with water, brine and then dried over sodium sulphate. The solvent was removed in vacuo and the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate) to afford ((R)-2-ethyl-3-oxo-isoxazolidin-4-yl)-carbamic acid tert-butyl ester as a yellow solid. LCMS (method A) 1.29 min, MH+(-BOC) 131; 1H-NMR (CDCl3, 400 MHz): 5.10 (m, 1H), 4.75 (m, 1H), 4.55 (m, 1H), 3.95 (m, 1H), 3.60 (m, 2H), 1.50 (s, 9H), 1.20 (m, 3H). The reaction mixture was partitioned between ethyl acetate and water The organic layer was washed with water, brine dried over sodium sulphate The solvent was removed in vacuo the crude product was purified by column chromatography (eluent cyclohexane/ethyl acetate)