| abstract |
Compounds of formula (I). <IMAGE> [wherein R<1> is hydrogen C1-10 alkyl, C3-7 cycloalkyl, C3-6 alkenyl, phenyl or phenyl-C1-3alkyl, and one of the groups represented by R<2>, R<3> and R<4> is hydrogen, C1-6 alkyl, C3-7 cycloalkyl, C2-6 alkenyl or phenyl-C1-3alkyl and each of the other two groups, which may be the same or different, is hydrogen or C1-6alkyl; and physiologically acceptable salts and solvates, e.g. hydrates, thereof] are potent selective antagonists at "neuronal" 5-hydroxytryptamine receptors and are useful in the treatment of migraine and psychotic disorders such as schizophrenia. |