Dimethyl Sulfoxide → tert-butyl N-[(2S)-1-oxo-3-phenylpropan-2-yl]carbamate

Participants

Reaction Conditions

Reaction Steps

A solution of 2.8 ml (40 mmol) of dry dimethylsulfoxide in 150 ml of dry dichloromethane was cooled under nitrogen atmosphere in a dry ice/chloroform bath (ca. -60° C.). In a separate flask, a 2M solution of oxalyl chloride in dichloromethane (15 ml, 30 mmol) was precooled to -60° C. and then added via cannula. After 10 min, a solution of 5 g (20 mmol) of N-((t-butyloxy)carbonyl)-phenylalaninol in 30 ml of dry dichloromethane was added via cannula. The resulting solution was stirred at -60° C. for 45 min, and was subsequently treated via syringe with 11 ml (80 mmol) of dry triethylamine. After being stirred for an additional 15 min at -60° C., the solution was quenched by addition of 10% aqueous citric acid, then immediately poured into a rapidly stirred mixture of 200 ml of 1:1 hexane:ether and 100 ml of 10% aqueous citric acid. The reaction flask was rinsed with ether which was added to the above mixture. The mixture was poured into a separatory funnel and the layers were sequentially with dilute layer was washed sequentially with dilute aqueous sodium bicarbonate and saturated brine, dried over MgSO4, and concentrated in vacuo to provide the crude desired compound.

Provenance & Evidence