Dimeric piperidine, tetrahydropyridine and piperazine derivatives

A dimeric 4-phenylpiperidine, 4-phenyl-1,2,3,6-tetrahydropyridine compound or a dimeric spirocyclic piperidine compound having the formula:

• ##STR6## wherein n is 1-5;
• R.sup.1 to R.sup.4 are independently selected from hydrogen, halogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, hydroxy, C.sub.1-6 alkylthio, C.sub.1-6 alkylsufonyl, C.sub.1-6 alkyl- or di-C.sub.1-6 alkyl)amino, cyano, trifluoromethyl, nitro, trifluoromethylthio or trifluoromethylsulfonyloxy;
• R.sup.5 and R.sup.6 are C.sub.2-3 alkyl linked together forming an ethylene or propylene bridge;
• X is O, S, SO, SO.sub.2, CO or (CH.sub.2).sub.m, m being 0 or 1, X is NR.sup.7, R.sup.7 being H, C.sub.1-6 alkyl, cycloalkyl, cycloalkylalkyl, phenyl or phenylalkyl, or X is CR.sup.8 R.sup.9, wherein R.sup.8 and R.sup.9 are independently selected from the group consisting of hydroxy and the substituents defined under R.sup.7, any phenyl group being optionally substituted with one or more substituents selected from the group consisting of halogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, hydroxy, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulfonyl, C.sub.1-6 alkyl or di(C.sub.1-6 alkyl)amino, cyano, trifluoromethyl and trifluoromethylthio;
• and
• Z.sup.1 and Y are linked together via a single bond, thereby forming a spirocyclic junction;
• wherein Y is C;
• Z.sup.1 is O, S, (CH.sub.2).sub.q, q being 1, 2 or 3, or Z.sup.1 is CH.sub.2 O, CH.sub.2 S, CH.sub.2 CH.sub.2 O, CH.sub.2 CH.sub.2 S, CH.dbd.CH, CH.dbd.CHCH.sub.2, CH.sub.2 OCH.sub.2, CH.sub.2 SCH.sub.2, CH.dbd.CH--O, or CH.dbd.CH--S;
• and Z.sup.2 is O, S, a bond or CH.sub.2 with the proviso that Z.sup.1 may not be O, S or (CH.sub.2).sub.q, wherein q is 1 when Z.sup.2 is a bond;
• or an acid addition salt thereof.