Indole-substituted five-membered heteroaromatic compounds as 5-HT.sub.1 agonists

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

• ##STR25## wherein the circle represents two non-adjacent double bonds in any position in the five-membered ring;
• W, X, Y and Z independently represent oxygen, sulphur, nitrogen or carbon, provided that one of W, X, Y and Z represents oxygen or sulphur and at least one of W, X, Y and Z represents carbon;
• A is selected from the group consisting of hydrogen, halogen, cyano, trifluoromethyl, nitro, --OR.sup.x, --OCOR.sup.x, --ONR.sup.x R.sup.y, --SR.sup.x, --NR.sup.x R.sup.y, --NR.sup.x OR.sup.y, --NR.sup.z NR.sup.x R.sup.y, --NR.sup.x COR.sup.y, --NR.sup.x CO.sub.2 R.sup.y, --NR.sup.x SO.sub.2 R.sup.y, --NR.sup.z CVNR.sup.x R.sup.y, --COR.sup.x, --CO.sub.2 R.sup.x, --CONR.sup.x R.sup.y, hydrocarbon selected from C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, C.sub.3-7 cycloalkyl, C.sub.3-7 cycloalkyl (C.sub.1-6)alkyl, aryl, aryl (C.sub.1-6)alkyl;
• heterocycloalkyl selected from azetidinyl, pyrrolidyl, piperidyl, piperazinyl and morpholinyl;
• heteroaryl selected from pyridyl, quinolyl, isoquinolyl, pyridazinyl, pyrimidinyl, pyrazinyl, pyranyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzthienyl, imidazolyl, oxadiazolyl and thiadiazolyl;
• heteroaryl (C.sub.1-6)alkyl;
• and
• heterocyclo (C.sub.1 -C.sub.6)alkyl;
• wherein said hydrocarbon, heterocyclo or heteroaryl group is unsubstituted or substituted by one or more groups selected from C.sub.1 -C.sub.6 alkyl, adamantyl, phenyl, halogen, C.sub.1-6 haloalkyl, C.sub.1-6 aminoalkyl, trifluoromethyl, hydroxy, C.sub.1-6 alkoxy, aryloxy, keto, C.sub.1-3 alkylenedioxy, nitro, cyano, carboxy, C.sub.2-6 alkoxycarbonyl, C.sub.2-6 alkoxycarbonyl (C.sub.1-6)alkyl, C.sub.2-6 alkylcarbonyloxy, arylcarbonyloxy, C.sub.2-6 alkycarbonyl, arylcarbonyl, C.sub.1-6 alkylthio, C.sub.1-6 alkylsuphinyl, C.sub.1-6 alkylsulphonyl, arylsulphonyl, --NR.sup.v R.sup.w, --NR.sup.v COR.sup.w, --NR.sup.v CO.sub.2 R.sup.w, --NR.sup.v SO.sub.2 R.sup.w, --CH.sub.2 NR.sup.v SO.sub.2 R.sup.w, --NHCONR.sup.v R.sup.w, --CONR.sup.v R.sup.w, --SO.sub.2 NR.sup.v R.sup.w and --CH.sub.2 SO.sub.2 NR.sup.v R.sup.w, in which R.sup.v and R.sup.w independently represent hydrogen, C.sub.1-6 alkyl, aryl or aryl(C.sub.1-6)alkyl, and R.sup.v and R.sup.w when taken together represent a C.sub.2-6 alkylene group;
• E represents a bond or a straight or branched alkylene chain containing from 1 to 4 carbon atoms;
• F represents a group of formula:
• ##STR26## R.sup.1 represents --CH.sub.2 --CHR.sup.4 --NR.sup.x R.sup.y or a group of formula:
• ##STR27## in which the broken line represents no bond or a single bond;
• R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently selected from the group consisting of hydrogen, C.sub.1-6 alkyl, C.sub.2-6 alkenyl and C.sub.2-6 alkynyl;
• R.sup.x and R.sup.y independently represent hydrogen or hydrocarbon, as defined above, or R.sup.x and R.sup.y together represent a C.sub.2-6 alkylene group;
• R.sup.z represents hydrogen or hydrocarbon, as defined above;
• V represents oxygen, sulphur or a group of formula .dbd.N--G;
• wherein G represents hydrocarbon as defined above, or an electron-withdrawing group selected from cyano, nitro, --COR.sup.x, --CO.sub.2 R.sup.x or --CO.sub.2 R.sup.x, in which R.sup.x is as defined above.