Piperidine derivatives having anxiolytic effect

A piperidine compound having Formula I:

• ##STR21## wherein R.sup.1 is a group having the general Formula II:
• ##STR22## wherein X is CHR.sup.10, O, S, SO, SO.sub.2 or NR.sup.10 ;
• wherein R.sup.10 is hydrogen, lower alkyl, lower alkenyl, sulfonyl, arylalkyl, phenyl or phenyl substituted with one or more substituents independently selected from the group consisting of halogen, lower alkyl, lower alkoxy, hydroxy, trifluoromethyl, and cyano;
• or
• R.sup.10 is a heteroaromatic group, selected from the group consisting of 2-thienyl, 3-thienyl, 2-furanyl, 3-furanyl, 2-thiazolyl, 2-oxazolyl, 2-imidazolyl, 2-pyridyl, 3-pyridyl, and 4-pyridyl;
• wherein one or two of the dotted lines may be a bond;
• when the dotted line emanating from Y indicates a bond, Y is N or CH;
• or when said dotted line indicates no bond, Y is CH.sub.2, or NH;
• R.sup.a -R.sup.d are independently selected from the group consisting of hydrogen, halogen, lower alkyl, trifluoromethyl and trifluoromethylthio;
• U is CH.sub.2, O or S;
• or
• when, one of the dotted lines emanating from U indicates a bond and U is CH;
• the bond between U and Q.sup.1 or Q.sup.2, respectively, may also be a triple bond and in such a case U is "C";
• Q.sup.1 is selected from a bond, C.sub.1 -C.sub.18 alkylene or C.sub.2 -C.sub.18 alkenylene and Q.sup.2 is C.sub.2 -C.sub.20 alkylene, C.sub.2 -C.sub.20 alkenylene or a group Q.sup.2 'D wherein Q.sup.2 ' is as defined for Q.sup.2 and D is CR.sup.8 R.sup.9 wherein R.sup.8 and R.sup.9 are independently selected from the substituents defined below for R.sup.4 -R.sup.7, and a cycloalkylene group;
• wherein Q.sup.1 and Q.sup.2 are optionally substituted with one or more hydroxy groups, any such hydroxy group being optionally esterified with an aliphatic carboxylic acid having from two to twenty-four carbon atoms, inclusive;
• wherein the total number of carbon atoms in Q.sup.1 and Q.sup.2 is from 3 to 20;
• and
• R.sup.2 and R.sup.3 are independently hydrogen, lower alkyl or they may be linked together thereby forming an ethylene or propylene bridge;
• R.sup.4 to R.sup.7 are independently selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy, trifluoromethyl and trifluoromethylthio;
• and
• Z.sup.1 is CH.sub.2, or O or S;
• Z.sup.2 and Z.sup.3 are independently (CH.sub.2).sub.n, wherein n is 0 or 1, O or S, with the proviso that Z.sup.1 may not be S or O when Z.sup.2 is S or O, and that Z.sup.2 and Z.sup.3 may not both be (CH.sub.2), wherein n is 0:
• or Z.sup.1 and Z.sup.2 taken together represent a group --CH.dbd.CH--;
• or when Z.sup.3 is (CH.sub.2).sub.n wherein n is 0, Z.sup.1 and Z.sup.2 taken together can form a 3-membered divalent group, optionally containing one unsaturated bond, and optionally containing one O- or S-heteroatom;
• with the proviso that the combination of Z.sup.1, Z.sup.2, and Z.sup.3 cannot represent a benzofuranyl system;
• and
• with the proviso that at least one of Z.sup.1, Z.sup.2 and Z.sup.3 is O or S;
• or
• an acid addition salt thereof.