THE PREPARATION METHOD OF (1 R,2S)-(-)-EPHEDRINE OR ITS HYDROCHLORIDE

摘要

IN this invention, (1 R,2S)-(-)-ephedrine is obtained by reacting, [(S)-(-)-α-methylaminophenylacetone]2 . (2R,3R)-tartaric acid derivatives or the salts of (S)-(-)-α-methylaminophenylacetone and other organic acids with metal borohydride or the mixture consisting of metal borohydride and lewis acid. Since the staring materials don't racemize during the reductive reaction, the ephedrine should be predominant in the product. In addition, the utilization of the metal borohydride is high.