The present invention relates to compounds of formula (I) wherein n is 3 and where any carbon atom of (CH.sub.2).sub.n may be substituted by R.sup.4 and/or R.sup.5 ; X represents O or S; R.sup.1 represents (CH.sub.2).sub.q phenyl, wherein q is 0, 1 , 2 or 3 which may be optionally substituted in the phenyl ring; R.sup.2 represents aryl selected from phenyl and naphthyl; heteroaryl selected from indazolyl, thienyl, furyl, pyridyl, thiazolyl, tetrazolyl and quinolyl; benzhydryl; or benzyl; wherein each aryl or heteroaryl moiety may be substituted; R.sup.4 and R.sup.5 each independently represent H, halo, C.sub.1-6 alkyl, oxo, CO.sub.2 R.sup.a or CONR.sup.a R.sup.b ; R.sup.6 represents H or C.sub.1-6 alkyl; R.sup.7 represents trifluoromethyl, C.sub.2-6 alkenyl, C.sub.3-7 cycloalkyl, C.sub.3-7 cycloalkylC.sub.1-4 alkyl, (CH.sub.2).sub.p NR.sup.9 R.sup.10, CO.sub.2 R.sup.16, CONR.sup.9 R.sup.10, (CH.sub.2).sub.p CO.sub.2 R.sup.16, (CH.sub.2).sub.p CONR.sup.9 R.sup.10, (CH.sub.2).sub.p NR.sup.9 COR.sup.16, (CH.sub.2).sub.p NHSO.sub.2 R.sup.11, (CH.sub.2).sub.p OR.sup.16, (CH.sub.2).sub.p OC(O)R.sup.9 or (CH.sub.2).sub.p OC.sub.1-4 alkylCOR.sup.17 or C.sub.1-6 alkyl substituted by a hydroxy group; R.sup.8 repents H, COR.sup.a, CO.sub.2 R.sup.a, COCONR.sup.a R.sup.b, COCO.sub.2 R.sup.a, C.sub.3-7 cycloalkyl, C.sub.3-7 cycloalkylC.sub.1-4 alkyl, C.sub.1-6 alkyl optionally substituted by a group selected from (CO.sub.2 R.sup.a, CONR.sup.a R.sup.b, hydroxy, cyano, COR.sup.a, NR.sup.a R.sup.b, C(NOH)NR.sup.a R.sup.b, CONHphenyl(C.sub.1-4 alkyl), COCO.sub.2 R.sup.a, CONHNR.sup.a R.sup.b, C(S)NR.sup.a R.sup.b, CONR.sup.a C.sub.1-6 alkylR.sup.12, CONR.sup.13 C.sub.2-6 alkynyl, CONR.sup.13 C.sub.2-6 alkenyl, COCONR.sup.a R.sup.b, CONR.sup.a C(NR.sup.b)NR.sup.a R.sup.b, CONR.sup.a heteroaryl, and optionally substituted phenyl or C.sub.1-6 alkyl, optionally substituted by oxo, substituted by an optionally substituted aromatic heterocycle; R.sup.a and R.sup.b each independently represent H, C.sub.1-6 alkyl, trifluoromethyl or phenyl optionally substituted by C.sub.1-6 alkyl, halo or trifluoromethyl. The compounds are of particular use in the treatment of pain, inflammation, migraine and emesis.