Carbazole derivatives and their use as 5HT-induced antagonists

The invention relates to compounds of the general formula (I): (I) wherein R1 represents a hydrogen atom or a C1-10 alkyl, C3-7 cycloalkyl, C3-7cycloalkyl-(C1-4)-alkyl, C3-6 alkenyl, C3-10 alkynyl, phenyl or phenyl-(C1-3)alkyl group; one of the groups represented by R2, R3 and R4 is a hydrogen atom or a C1-6 alkyl, C3-7 cycloalkyl, C2-6 alkenyl 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 X represents a halogen atom or a hydroxy, C1-4 alkoxy, phenyl-(C1-3)-alkoxy or C1-6 alkyl group or a group NR5R6 or CONR5R6 wherein R5 and R6, 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 compounds are potent and selective antagonists of "neuronal" 5-hydroxytryptamine receptors and are useful in the treatment of psychotic disorders (e.g. schizophrenia and mania;); anxiety, pain; gastric stasis; symptoms of gastrointestinal dysfunction such as occur with dyspepsia, peptic ulcer, reflux oesophagitis and flatulence; migraine; and nausea and vomiting.