Dimethyl Sulfoxide → (2S)-1-tert-butoxycarbonyl-2-phenylpiperidin-3-one

Participants

Reaction Conditions

Reaction Steps

Dimethyl sulfoxide (20.80 mL, 22.90 g, 29.3 mmol) in dichloro-methane (75 mL) was added dropwise to a cooled (−70° C.) solution of oxalyl chloride (13.96 mL, 20.30 g, 160 mmol) in dichloromethane (350 mL). The mixture was stirred at −70° C. for 15 min., then (2S,3S)-1-tert-butoxycarbonyl-3-hydroxy-2-phenylpiperidine (36.91 g. 133 mmol) in dichloromethane (150 mL) was added dropwise. The mixture was stirred at −70° C. for 20 min., then allowed to warrn to −30° C. The mixture was cooled to —50° C. and triethylamine (55.95 mL, 40.45 g, 400 mmol) was added slowly. The mixture was allowed to warm to 0° C. and diluted with ice-cooled dichloromethane (250 mL). The mixture was washed with ice cold aqueous citric acid solution (5%, 2×300 mL) and water (300 mL), dried (MgSO4), and the solvent was evaporated under reduced pressure to give (2S)-1-tert-butoxycarbonyl-2-phenylpiperidin-3-one as a yellow oil (42.3 g). 1H NMR (250 MHz, CDC13) 7.5-7.3(5H, m), 5.8 (1H, br s), 4.2(1H, br s), 3.4 (1H, m), 2.6 (2H, m), 2.0 (2H, 1.54 (9H, s).

Provenance & Evidence