Process for preparing optically active 3-hydroxy-1,5-benzothiazepine derivative and intermediate therefor

摘要

An optical resolution process of the compound of the formula Ä1Ü : wherein Ring A and Ring B are a substituted or unsubstituted benzene ring and R<1> and R<2> are the same or different and a lower alkyl group, by utilizing difference in solubility between the two diastereoisomeric salts prepared by treating the racemic compound Ä1Ü with an optically active d- or 1-3-bromocamphor-9-sulfonic acid or a salt thereof. The present process is industrially advantageous with compared to conventional processes for preparing an optically active 3-hydroxy-1,5-benzothiazepine derivative which are useful as an intermediate for preparing medicines.