Process

摘要

The present invention relates to a process for preparing a pharmaceutical starting compound compound by hydrolyzing a compound of the general formula (II): Wherein R¹ is protected carboxy, R² is lower alkoxy or higher alkoxy, A¹ is an aromatic bivalent group, heterocyclic bivalent group or cyclo (lower) alkane bivalent group, and A² is an aromatic bivalent group, heterocyclic bivalent group or cyclo (lower) alkane bivalent group, with aqueous potassium hydroxide and by treating with hydrochloric acid.