Method for resolving chiral (2s) and (2r) chromanes

摘要

Disclosed are processes for resolving chiral (2S) and (2R) benzopyrans, racemizing benzopyrans, and recycling racemized benzopyrans to increase yield of a desired enantiomer to provide purified or substantially purified bicyclic amino substituted benzopyran derivatives. Such benzopyran derivatives are preferably chromans which can be coupled with benzoyl derivatives via an amide bond to produce potent platelet aggregation inhibitors.