Abstract: The present invention provides ketones of the general formula (I): ##STR1## and physiologically acceptable salts and solvates thereof, wherein R.sup.1 and R.sup.2, which may be the same or different, each represents a hydrogen atom or a C.sub.1-6 alkyl group; Im represents an imidazolyl group of formula: ##STR2## wherein one of the groups represented by R.sup.3, R.sup.4 and R.sup.5 is a hydrogen atom or a C.sub.1-6 alkyl, C.sub.3-7 cycloalkyl, C.sub.3-6 alkenyl, phenyl or phenyl C.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; and an aromatic or heteroaromatic group as defined in the specification.The compounds are potent and selective antagonists of the effect of 5-HT at 5-HT.sub.3 receptors and are useful, for example, in the treatment of psychotic disorders, anxiety and nausea and vomiting.

Abstract: The invention relates to compounds of formula (I): ##STR1## and physiologically acceptable salts or solvates thereof, wherein Im represents an imidazolyl group of formula: ##STR2## and the various substituents are defined hereinbelow. The compounds are potent and selective antagonists of the effect of 5-HT at 5-HT.sub.3 receptors and are useful, for example, in the treatment of psychotic disorders, anxiety, and nausea and vomiting.