Compounds of formula (I), ##STR00001## or pharmaceutically acceptable derivatives thereof, wherein: R.sup.1 represents H, C.sub.1-6-alkyl, C.sub.1-6alkyloxy, C.sub.3-8cycloalkyl, or halo; R.sup.2 represents H, C.sub.1-6alkyl (optionally substituted by R.sup.3), phenyl (optionally substituted by CN), or Het; R.sup.3 represents OH, CN, Het, --R.sup.4--C.sub.1-6alkyl, or CONR.sup.5R.sup.6; R.sup.4 represents --CO.sub.2--, or --O--; R.sup.5 and R.sup.6 independently represent H, C.sub.1-6alkyl (optionally substituted by OR.sup.7) or C.sub.3-8cycloalkyl; R.sup.7 represents H or C.sub.1-6alkyl; Het represents a five or six membered aromatic heterocyclic group containing (i) from one to four nitrogen heteroatom(s) or (ii) one or two nitrogen heteroatom(s) and one oxygen or one sulphur heteroatom or (iii)one or two oxygen or sulphur heteroatom(s), said heterocyclic group being optionally substituted by one or more groups selected from CN and C.sub.1-6alkyl; R.sup.8 represents C.sub.1-6alkyl, C.sub.1-6alkyloxy, C.sub.3-8cycloalkyl, or halo; R.sup.9 and R.sup.10 independently represent H, C.sub.1-6alkyl, C.sub.1-6alkyloxy, CN, CF.sub.3 or halo; may be useful for treating endometriosis, uterine fibroids (leiomyomata), menorrhagia, adenomyosis, primary and secondary dysmenorrhoea (including symptoms of dyspareunia, dyschexia and chronic pelvic pain), or chronic pelvic pain syndrome.