Piperazine, piperidine and tetrahydropyridine derivatives useful as 5-HT1 recepter agonists

A compound of formula I, or a salt or prodrug thereof:

• ##STR26## wherein Z represents --SO.sub.2 NR.sup.5 R.sup.6, or a group of formula (b), ##STR27## in which the asterisk * denotes a chiral centre;
• X represents oxygen,
• Y represents oxygen or sulphur;
• E represents a chemical bond or a straight or branched alkylene chain containing from 1 to 4 carbon atoms;
• Q represents a straight or branched alkylene chain containing from 1 to 6 carbon atoms, optionally substituted in any position by a hydroxy group;
• T represents CH;
• U represents nitrogen or C--R.sup.2 ;
• V represents oxygen, sulphur or N--R.sup.3 ;
• --F--G-- represents --CH.sub.2 --N--,
• R.sup.1 represents aryl(C.sub.1-6)alkyl or heteroaryl(C.sub.1-6)alkyl, either of which groups may be optionally substituted;
• R.sup.2, R.sup.3 and R.sup.4 independently represent hydrogen or C.sub.1-6 alkyl;
• and
• R.sup.5 and R.sup.6 independently represent hydrogen, C.sub.1-6 alkyl, trifluoromethyl, phenyl, methylphenyl, or an optionally substituted aryl(C.sub.1-6)alkyl or heteroaryl(C.sub.1-6)alkyl group;
• or R.sup.5 and R.sup.6, when linked through a nitrogen atom, together represent the residue of an optionally substituted azetidine, pyrrolidine, piperidine, morpholine or piperazine ring.