Optically active benzothiazepine compounds and process for preparing the same

摘要

An optically active salt of 1,5-benzothiazepine compound of the formula (I) or (II): wherein each of Ring A and Ring B is a substituted or unsubstituted benzene ring, and R1 and R2 are the same or different and each is a lower alkyl group, can be prepared by resolving a racemic salt of 1,5-benzothiazepine compound of the formula (I) or (II) by means of preferential crystallization.