benzyl N-(2-oxobutyl)carbamate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To methylene chloride (60 mL) at −78° C. under argon was added oxalyl chloride (37 mL of 2 M solution in methylene chloride, 74 mmol), followed by DMSO (7.8 g, 100 mmol). The mixture was stirred at −78° C. for 20 min. and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-butanol (13.9 g, 61.8 mmol) in methylene chloride (40 mL). The mixture was stirred at −78° C. for 1 h and triethylamine (21 mL) was added to the mixture. It was warmed to room temperature (rt) and washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution. The methylene chloride solution was dried over MgSO4 and concentrated to afford 1-benzyloxycarbonylamino-2-butanone (11.2 g, 82%) as a solid, which was enough pure for the next reaction. The mixture was stirred at −78° C. for 1 h It was warmed to room temperature (rt) washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution The methylene chloride solution was dried over MgSO4 concentrated

Conditions: temp:78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To methylene chloride (60 mL) at -78° C. under argon was added oxalyl chloride (37 mL of 2 M solution in methylene chloride, 74 mmol), followed by DMSO (7.8 g, 100 mmol). The mixture was stirred at 78° C. for 20 min. and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-butanol (13.9 g, 61.8 mmol) in methylene chloride (40 mL). The mixture was stirred at -78° C. for 1 h and triethylamine (21 mL) was added to the mixture. It was warmed to room temperature (rt) and washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution. The methylene chloride solution was dried over MgSO4 and concentrated to afford 1-benzyloxycarbonylamino-2-butanone (11.2 g, 82%) as a solid, which was enough pure for the next reaction. 1H NMR (CDCl3) δ7.32 (m, 5 H), 5.50 (s, 1 H), 5.06 (s, 2 H), 4.07 (s, 2 H), 2.43 (q, J=7.6 Hz, 2 H), 1.06 (t, J=7.6 Hz, 3 H). The mixture was stirred at -78° C. for 1 h It was warmed to room temperature (rt) washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution The methylene chloride solution was dried over MgSO4 concentrated

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To methylene chloride (60 mL) at −78° C. under argon was added oxalyl chloride (37 mL of 2 M solution in methylene chloride, 74 mmol), followed by DMSO (7.8 g, 100 mmol). The mixture was stirred at −78° C. for 20 min. and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-butanol (13.9 g, 61.8 mmol) in methylene chloride (40 mL). The mixture was stirred at −78° C. for 1 h and triethylamine (21 mL) was added to the mixture. It was warmed to room temperature (rt) and washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution. The methylene chloride solution was dried over MgSO4 and concentrated to afford 1-15 benzyloxycarbonylamino-2-butanone (11.2 g, 82%) as a solid, which was enough pure for the next reaction. The mixture was stirred at −78° C. for 1 h It was warmed to room temperature (rt) washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution The methylene chloride solution was dried over MgSO4 concentrated

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To methylene chloride (60 mL) at −78° C. under argon was added oxalyl chloride (37 mL of 2 M solution in methylene chloride, 74 mmol), followed by DMSO (7.8 g, 100 mmol). The mixture was stirred at −78° C. for 20 min. and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-butanol (13.9 g, 61.8 mmol) in methylene chloride (40 mL). The mixture was stirred at −78° C. for 1 h and triethylamine (21 mL) was added to the mixture. It was warmed to room temperature (rt) and washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution. The methylene chloride solution was dried over MgSO4 and concentrated to afford 1-benzyloxycarbonylamino-2-butanone (11.2 g, 82%) as a solid, which was enough pure for the next reaction. The mixture was stirred at −78° C. for 1 h It was warmed to room temperature (rt) washed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution The methylene chloride solution was dried over MgSO4 concentrated