1-(aryl or heteroaryl)-4[.omega.-(aryl or heteroaryl).omega.-(aryl or heteroaryl)alkylene]piperazines

A compound of the formula (I) ##STR14## or a pharmaceutically acceptable acid addition salt thereof, wherein W is (CH.sub.2).sub.m, CHOH or O,

• m is one of the integers 1 or 2,
• A is an alkylene chain of 1 to 3 carbon atoms optionally substituted by one or more (lower)alkyl groups,
• R is hydrogen or lower alkyl,
• R.sup.1 and R.sup.2 are each, independently, phenyl, naphthyl, pyridinyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolyl, triazolyl or tetrazolyl each of which may be optionally substituted by one or more substituents selected from lower alkyl, lower alkoxy, halogen, halo(lower)alkyl, nitro, amino, (lower)alkylamino, di(lower)alkylamino, phenyl, halophenyl, (lower)alkylphenyl or (lower)alkoxyphenyl,
• R.sup.3 is hydrogen or lower alkyl and
• R.sup.4 is phenyl, naphthyl, pyridinyl, pyrimidinyl, pyrazinyl, quinolinyl, or isoquinolinyl each of which may be optionally substituted by one or more substituents selected from lower alkyl, lower alkoxy, halogen, halo(lower)alkyl, nitro, amino, (lower)alkylamino, di(lower)alkylamino, phenyl, halophenyl, (lower)alkylphenyl (lower)alkoxyphenyl, hydroxy, hydroxy(lower)alkyl, and --CONR.sup.5 R.sup.6 (where R.sup.5 and R.sup.6 are each hydrogen, lower alkyl or --NHSO.sub.2 (lower)alkyl).