Pyrido[1,2-a]pyrimidine derivatives

摘要

Compounds of the formula: <IMAGE> or pharmaceutically acceptable acid addition or quaternary ammonium salts thereof wherein R2 is C1 to C6 alkyl: R3 is C1 to C6 alkyl; R4 is a single electron pair, hydrogen or lower alkyl; and the dotted lines indicate saturated or unsaturated bonds, are disclosed with analgesic properties.