Ethanol → 1,1-Dimethylethyl N-((1S,2S)-3-chloro-2-hydroxy-1-(phenylmethyl)propyl)carbamate

Participants

Reaction Conditions

Reaction Steps

Ethyl acetate (4.2 ml) and ethanol (16.7 ml) were added to (3S)-3-tert-butoxycarbonylamino-1-chloro-4-phenyl-2-butanone (2.08 g), and sodium borohydride (133 mg) was charged in divided portions at −10° C. The mixture was stirred for 1 hour and 40minutes. To the reaction solution was added acetic acid (0.40 ml) to terminate the reaction. The solution was heated at 60° C. over 1 hour, and further stirred at 60° C. for 30 minutes. Subsequently, the reaction solution was cooled to −10° C. over 1 hour and 50 minutes, and further stirred at −10° C. for 6 hours. Crystals obtained were collected by filtration, washed with water of 0° C., and dried under reduced pressure to obtain desired (2S,3S)-3-tert-butoxycarbonylamino-1-chloro-2-hydroxy-4-phenylbutane (1.52 g). The dry crystals were analyzed by HPLC, and found to be crystals having a quality of (2S,3S):(2R,3S)=98.5:1.5.

Provenance & Evidence