Process for preparing optically active benzothiazepine compound and

Abstract

Powdery aggregate of 2-phenyl-1,5-benzothiazepin-3,4(2H,5H)-dione compound: ##STR1## wherein Ring A and Ring B are benzene ring having optionally substituent selected from lower alkyl, lower alkoxy and halogen, which is prepared by admixing solution of the compound (II) in polar organic solvent with solvent which does not substantially dissolve the compound (II) but is miscible with said polar organic solvent, and separating and collecting the resultant particles of the compound (II). Said aggregate of the compound (II) can be converted into optically active 3-hydroxy-2-phenyl-2,3-dihydro-1,5-benzothiazepin-4(5H)-one compounds (I) on industrial scale, which are useful as intermediate for various medicaments.