Abstract: Compounds of general formula (I) ##STR1## wherein R.sup.1 represents a phenyl, C.sub.3-7 cycloalkyl, C.sub.7-11 bridgedcycloalkyl or C.sub.1-6 alkyl group which alkyl group may be substituted by a hydroxy, phenyl, C.sub.1-6 alkoxycarbonyl, C.sub.3-7 cycloalkyl, or C.sub.3-7 bridgedcycloalkyl group;R.sup.2 represents phenyl substituted by a group (CH.sub.2).sub.n NR.sup.4 R.sup.5, O(CH.sub.2).sub.p R.sup.6, or (CH.sub.2).sub.n CO.sub.2 R.sup.11 ;R.sup.3 represents phenyl optionally substituted by one or 2 halogen atoms;R.sup.4 represents hydrogen or C.sub.1-4 alkyl;R.sup.5 represents acyl, or C.sub.2-4 alkyl substituted by one or more hydroxy; carboxyl and/or amino groups or R.sup.4 and R.sup.5 together with the nitrogen atom to which they are attached form a 5-7 saturated heterocyclic ring which contain an additional heteroatom selected from oxygen, sulphur or nitrogen and/or may be substituted by 1 or 2 C.sub.1-4 alkyl or hydroxy groups.R.sup.6 represents hydroxy, C.sub.1-4 alkoxy, CO.sub.2 R.sup.7 or NR.