Abstract: Compounds of formula (I), and their pharmaceutically acceptable derivatives, wherein R.sup.1 and R.sup.2 are optional substituents and independently represent C.sub.1-6 alkyl, C.sub.2-6 alkenyl [optionally substituted by CO.sub.2 H or CO.sub.2 (C.sub.1-6 alkyl)], C.sub.2-6 alkynyl, halogen, C.sub.1-3 perfluoroalkyl, (CH.sub.2).sub.m Ar.sup.1, (CH.sub.2).sub.m Het.sup.1, (CH.sub.2).sub.m CONR.sup.7 R.sup.8, (CH.sub.2).sub.m CO.sub.2 R.sup.8, O(CH.sub.2).sub.q CO.sub.2 R.sup.8, (CH.sub.2).sub.m COR.sup.8, (CH.sub.2).sub.m OR.sup.8, O(CH.sub.2).sub.p OR.sup.8, (CH.sub.2).sub.m NR.sup.7 R.sup.8, CO.sub.2 (CH.sub.2).sub.q NR.sup.7 R.sup.8, (CH.sub.2).sub.m CN, S(O).sub.n R.sup.8, SO.sub.2 NR.sup.7 R.sup.8, CONH(CH.sub.2).sub.m Ar.sup.1 or CONH(CH.sub.2).sub.m Het.sup.1 ; R.sup.3 represents H, C.sub.1-6, alkyl, (CH.sub.2).sub.p NR.sup.9 R.sup.10, SO.sub.2 R.sup.10, SO.sub.2 NR.sup.9 R.sup.10, (CH.sub.2).sub.m COR.sup.10, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, (CH.sub.2).sub.m CONR.sup.9 R.sup.10, (CH.sub.2).sub.

Abstract: The present invention provides a compound of formula I: ##STR1## or a salt thereof, wherein: the dotted lines represent optional double bonds;R.sup.1 represents hydrogen, hydroxy, alkenyl, alkyl, aminoalkyl or hydroxyalkyl;R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 independently represet hydrogen, hydroxy, fluoro, alkenyl, aryl, alkyl, or alkyl substituted with aryl, amino, hydroxy, carboxy or fluoro; andR.sup.7, R.sup.8, R.sup.9 and R.sup.10 independently represent hydrogen, hydrocarbon or a heterocyclic group provided that R.sup.7, R.sup.8, R.sup.9 and R.sup.10 are not simultaneously hydrogen; orR.sup.7 and R.sup.8 and/or R.sup.9 and R.sup.10 may complete a saturated or unsaturated C.sub.4-9 hydrocarbon or heterocyclic ring; which compounds are useful as anticonvulsant agents and in the treatment and/or prevention of neurodegenerative disorders.