| abstract |
The present invention relates to a process for preparing a pharmaceutical starting compound compound by hydrolyzing a compound of the general formula (II): Wherein R 1 is protected carboxy, R 2 is lower alkoxy or higher alkoxy, A 1 is an aromatic bivalent group, heterocyclic bivalent group or cyclo(lower)alkane bivalent group, and A 2 is an aromatic bivalent group, heterocyclic bivalent group or cyclo(lower)alkane bivalent group, with aqueous potassium hydroxide and by treating with hydrochloric acid. |