Hydrochloric Acid → (2R,3S)-3-(t-butoxycarbonyl)amino-4-phenyl-butane-1,2-diol

Participants

Reaction Conditions

Reaction Steps

A solution of N-tert-butoxycarbonyl-3(S)-amino-2(R)-hydroxy-4-phenylbutyric acid methyl ester 154.7 g dissolved in ethanol 300 ml was kept at 5-15° C. and mixed with sodium borohydride 24.6 g and stirred at 15-45° C. for 3hrs. The reaction solution was cooled and adjusted with 3N-HCl to pH 2.5-3.5. Water was added to the resultant solution and then the obtained solution was cooled to 5° C. or lower to deposit crystals. The crystals were filtered, dissolved in ethyl acetate, and washed with aqueous 5% sodium bicarbonate solution to separate an organic phase, which was washed with aqueous 10% sodium chloride solution and concentrated under an reduced pressure to obtain the crude N-tert-butoxycarbonyl-3(S)-amino-2(R)-hydroxy-4-phenyl-1-butanol.

Provenance & Evidence