Lactam derivatives

A compound of formula (I) ##STR17## wherein Im represents an imidazolyl group of the formula:

• ##STR18## and R.sup.1 represents a hydrogen atom or a group selected from C.sub.1-6 alkyl, C.sub.3-6 alkenyl, C.sub.3-10 alkynyl, C.sub.3-7 cycloalkyl, C.sub.3-7 cycloalkylC.sub.1-4 alkyl-, phenyl, phenylC.sub.1-3 alkyl-, --CO.sub.2 R.sup.5, --COR.sup.5, --CONR.sup.5 R.sup.6 or --SO.sub.2 R.sup.5 (wherein R.sup.5 and R.sup.6, which may be the same or different, each represents a hydrogen atom, a C.sub.1-6 alkyl or C.sub.3-7 cycloalkyl group, or a phenyl or phenylC.sub.1-4 alkyl- group, in which the phenyl group is optionally substituted by one or more C.sub.1-4 alkyl, C.sub.1-4 alkoxy or hydroxy groups or halogen atoms, with the proviso that R.sup.5 does not represent a hydrogen atom when R.sup.1 represents a group --CO.sub.2 R.sup.5 or --SO.sub.2 R.sup.5);
• one of the groups represented by R.sup.2, R.sup.3 and R.sup.4 is a hydrogen atom or a C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, C.sub.3-6 alkenyl, phenyl or phenylC.sub.1-3 alkyl- group, and each of the other two groups, which may be the same or different, represents a hydrogen atom or a C.sub.1-6 alkyl group;
• Y represents the group CH.dbd.CH or (CH.sub.2).sub.n, wherein n represents 2 or 3;
• Q represents a halogen atom, or a group selected from hydroxy, C.sub.1-4 alkoxy, phenylC.sub.1-3 alkoxy-, C.sub.1-6 alkyl, cyano, phenyl which may be unsubstituted or substituted by one or more C.sub.1-4 alkyl, C.sub.1-4 alkoxy or hydroxy groups or halogen atoms, --NR.sup.7 R.sup.8, --CONR.sup.7 R.sup.8 or --(CH.sub.2).sub.p CONR.sup.7 R.sup.8 (wherein R.sup.7 and R.sup.8, which may be the same or different, each represents a hydrogen atom or a C.sub.1-4 alkyl or C.sub.3-4 alkenyl group;
• and p represents 1, 2 or 3), --(CH.sub.2).sub.q NR.sup.9 R.sup.10 (wherein R.sup.9 represents a hydrogen atom or a C.sub.1-4 alkyl group, and R.sup.10 represents a group --COR.sup.11 or --SO.sub.2 R.sup.11 wherein R.sup.11 represents a C.sub.1-4 alkyl group;
• and q represents 0, 1, 2 or 3), or --(CH.sub.2).sub.2 CO.sub.2 R.sup.11 (R.sup.11 being as defined previously);
• Q' represents a hydrogen or a fluorine atom;
• or a physiologically acceptable salt or solvate thereof.