A compound of formula (I) ##STR00001## wherein R.sup.1 is a C.sub.1-6 straight or branched chain alkyl group, a C.sub.2-6alkenyl group, a C.sub.2-6 alkynyl group, a C.sub.3-6cycloalkyl group or a C.sub.3-6cycloalkylC.sub.1-6alkyl group, each optionally substituted by one to three groups independently selected from: --CN; --NO.sub.2; a group --COR.sup.2 wherein R.sup.2 is hydrogen, C.sub.1-6 alkyl, --OR.sup.3 wherein R.sup.3 is hydrogen or C.sub.1-6alkyl or NR.sup.4R.sup.5 wherein R.sup.4 and R.sup.5 are independently selected from hydrogen or C.sub.1-6 alkyl; a group --S(O).sub.mR.sup.6 wherein m is 0, 1 or 2, R.sup.6 is hydrogen, C.sub.1-6 alkyl, hydroxy or NR.sup.7R.sup.8 wherein R.sup.7 and R.sup.8 are independently hydrogen or C.sub.1-6 alkyl; a group PO(OR.sup.9).sub.2 wherein R.sup.9 is hydrogen or C.sub.1-6 alkyl; a group NR.sup.10R.sup.11 wherein R.sup.10 and R.sup.11 are independently selected from hydrogen, C.sub.1-6 alkyl, --COR.sup.12 wherein R.sup.12 is hydrogen or C.sub.1-6 alkyl, or --S(O).sub.m'R.sup.13 wherein m' is 0, 1 or 2 and R.sup.13 is hydrogen or C.sub.1-6 alkyl; halo; or a group --OR.sup.14 wherein R.sup.14 is hydrogen, C.sub.1-6 alkyl optionally substituted by one to three halo atoms, C.sub.6-10 aryl or --COR.sup.15 wherein R.sup.15 is hydrogen or C.sub.1-6 alkyl; p is 2 or 3, q is 1 or 2 and n is 0 or 1 and all salts, esters, amides and physiologically acceptable prodrugs thereof; pharmaceutical uses and formulations therefor; and processes for their preparation are disclosed.