PROCESS FOR RESOLVING CHIRAL INTERMEDIATES USED IN MAKING CALCIUM CHANNEL BLOCKERS

摘要

HA504 PROCESS FOR RESOLVING CHIRAL INTERMEDIATES USED IN MAKING CALCIUM CHANNEL BLOCKERS This process enables preparation of the preferred (+)-threo enantiomer by resolution of its racemic mixture of a compound of the formula , wherein Y1 and Y2 are each independently lower alkyl and R1 is hydrogen or lower alkyl. The compound is treated with a chiral acid (tartaric acid preferred) in an organic solvent (ethanol preferred) to yield the (+)-threo enantiomer, which is then recovered from the reaction mixture. This enantiomer may then be used to produce the preferred (+)-cis enantiomor of certain benzothiazepine cardiovascular agents.