Piperid-4-yl ureas and thio ureas used as anti-depressant agents

Abstract

The invention concerns compounds of formula ##STR1## and acid addition and quaternary ammonium salts thereof, wherein the dotted line represents an optional bond, Ar represents a ring system of formula ##STR2## in which Q is O,S,--CR.sup.7 .dbd.CR.sup.8 --, --N.dbd.CR.sup.8 -- and --N.dbd.N--; R.sup.4, R.sup.5 and R.sup.6, and R.sup.7 and R.sup.8 when present, each represent hydrogen or defined substituents and additionally either R.sup.4 and R.sup.5 when adjacent or R.sup.6 and R.sup.8 when adjacent, together with the carbon atoms to which they are attached also represent a fused five or six membered carbocyclic or heterocyclic ring optionally carrying one or more defined substituents; R is an optionally substituted aryl or heteroaryl radical or a cycloalkyl radical containing 5 to 7 carbon atoms; R.sup.1, R.sup.2, R.sup.3 and R.sup.9 are each hydrogen or a lower alkyl group; n is 0 or 1; X is .dbd.O, .dbd.S or .dbd.NH; Y is --O-- or a direct bond and Z is --CO-- or --CH.sub.2 -- with the proviso that when Ar is unsubstituted phenyl and R.sup.9 is hydrogen then Y is --O--. The compounds of formula I exhibit psychotropic activity and are useful as antidepressants. Processes for preparing the compounds and pharmaceutical compositions containing them are disclosed.