| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high purity optically active 3-hydroxy-1,5-benzothiazepine derivative by optically resolving a racemic compound thereof by using an optically active 3-bromocamphor-9-sulfonic acid as an optically resolving agent to form a diastereomer. SOLUTION: This optically active 3-hydroxy-1,5-benzothiazepine derivative is obtained by reacting d- or 1-3-bromocamphor-9-sulfonic acid or salt thereof as an optically resolving agent with a cis-3-hydroxy-1,5-benzothiazepine derivative of formula I (rings A, B arc each a subtsitutable benzene ring; R<1> , R<2> are each a lower alkyl) in a solvent (e.g. methanol) at a room temperature to a boiling point of the solvent or lower to form two kinds of diastereomer salts expressed by formula II, crystallizing one of the salts having lower solubility by taking advantage of the difference in their solubilities, and separating. The separated diastereomer salt can be converted to a free base or an acid adduct salt other than the diastereomer by a commonly known method. |
