PROCESS FOR THE PREPARATION OF PYRIDO [2,1-a] ISOQUINOLINE DERIVATIVES COMPRISING OPTICAL RESOLUTION OF AN ENAMINE

摘要

This invention relates to a process for the preparation of pyrido[2,1-a]isoquinoline derivatives of the formula wherein R¹, R², R³ and R⁴ are defined in the specification, comprising the optical resolution of an enamine of the formula wherein R¹ is lower alkyl, in the presence of an optical active resolving agent to form an (S)-enamine salt of the formula wherein RCO₂^- is the conjugate base of the resolving agent.