PROCESS FOR PREPARING PIPERIDINE DERIVATIVES

摘要

Compounds of the general formula I: I wherein R1 represents a thienyl group, or a phenyl group optionally substituted by a halogen (preferably fluorine or chlorine) atom, a lower alkoxy or lower alkyl group, R2 represents a hydrogen or halogen (preferably fluorine) atom, a lower alkoxy or lower alkyl group, R3 represents a hydrogen or halogen (preferably fluorine) atom, a lower alkylthio, lower alkoxy or lower alkyl group, or a cycloalkyl group containing 5 or 6 carbon atoms, or a group of the general formula: II wherein R4 and R5 singly each represents a hydrogen atom or lower alkyl group, R6 represents a cycloalkyl, hydroxymethyl, carboxy or lower alkoxycarbonyl group, and W represents a carbonyl or a hydroxymethylene [viz. -CH(OH)-] group, and pharmacologically acceptable salts thereof possess potent selective Histamine H1-receptor blocking and calcium antagonist properties and are of interest in the treatment of a variety of respiratory, allergenic and cardiovascular disease states. The new compounds can be prepared by various methods based on the condensation of alpha -substituted benzyl halides with N-(benzoylpropyl or phenyl-hydroxypropyl)-4-hydroxy piperidines or condensation of di-substituted-methoxy-piperidines with a benzoylpropyl halide or a phenyl-hydroxypropyl-halide followed, where necessary, by removal of protecting groups.