PIPERIDINE DERIVATIVES, THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

"PIPERIDINE DERIVATIVES, THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM" Piperidine derivatives which are compounds of formula (I) wherein Ar1 and Ar2 independently represent a phenyl group optionally substituted by a halogen atom, a thienyl group or a pyridinyl group, A represents an alkylene group of 2 to 6 carbon atoms, X represents a CO group or a bond, R1 represents a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, either R2 represents a hydrogen atom and R3 represents a hydrogen atom or a hydroxy group, or R2 and R3 together represent a bond, and R4 represents a hydrogen or halogen atom, or pharmaceutically acceptable acid addition salts thereof are useful as antiallergics and antipruritics.