Indole derivatives

The invention relates to compounds of formula (I) (I) wherein R1 represents a hydrogen atom or a group selected from C1-10 alkyl, C3-6 alkenyl, C3-10 alkynyl, C3-7 cycloalkyl, C3-7 cycloalkyl C1-4 alkyl, phenyl, or phenyl C1-3 alkyl, -CO2R10, -COR10, -CONR10R11 or -SO2R10 (wherein R10 and R11, which may be the same or different, each represents a hydrogen atom, a C1-6 alkyl or C3-7 cycloalkyl group, or a phenyl or phenylC1-4 alkyl group, in which the phenyl group is optionally substituted by one or more C1-4 alkyl, C1-4 alkoxy or hydroxy groups or halogen atoms, with the proviso that R10 does not represent a hydrogen atom when R1 represents a group -CO2R10 or -SO2R10); R2 represents a hydrogen atom or a C1-6 alkyl, C3-6 alkenyl, C3-7 cycloalkyl, phenyl or phenyl C1-3 alkyl group; R3 and R4, which may be the same or different, each represents a hydrogen atom or a C1-6 alkyl group; One of the groups represented by R5, R6 and R7 is a hydrogen atom or a C1-6 alkyl, C1-6 hydroxyalkyl, C3-7 cycloalkyl, C2-6 alkenyl, phenyl or phenyl C1-3 alkyl group, and each of the other two groups, which may be the same or different, represents a hydrogen atom or a C1-6 alkyl group; and Q represents a hydrogen or a halogen atom, or a hydroxy, C1-4 alkoxy, phenyl C1-3 alkoxy or C1-6 alkyl group or a group -NR8R9 or -CONR8R9 wherein R8 and R9, which may be the same or different, each represents a hydrogen atom or a C1-4 alkyl or C3-4 alkenyl group, or together with the nitrogen atom to which they are attached form a saturated 5 to 7 membered ring; and physiologically acceptable salts and solvates thereof. The comopounds are potent and selective antagonists of the effect of 5-HT at 5-HT3 receptors and are useful, for example, in the treatment of psychotic disorders, anxiety, and nausea and vomiting.