Dimethyl Sulfoxide → Benzyl (2-oxobutyl)carbamate

Temperature

78 °C

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).

1. stirringThe mixture was stirred at -78° C. for 1 h
2. temperatureIt was warmed to room temperature (rt)
3. washwashed successively with 1 N hydrochloric acid and aqueous sodium bicarbonate solution
4. dry with materialThe methylene chloride solution was dried over MgSO4
5. concentrationconcentrated

ORD record

ord-6faffb2e63ef489496f55f0ef0121394

Source dataset

uspto-grants-2000_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06040321