CHEMICAL COMPOUND

Indoles are disclosed of formula (I): whereinR₁ represents R₅R₆NCOCH₂-, R₅CONH(CH₂)p-, R₅R₆NSO₂(CH₂)p- or R₇SO₂NH(CH₂)p-, (where R₅ and R₆ each represents a hydrogen atom or a C1-3 alkyl group, R₇ represents C1-3 alkyl and p is zero or one),R₂ is hydrogen or C1-3 alkyl;R₃ and R₄ each represents hydrogen atom, C1-3 alkyl, or 2-propenyl;m is zero or an integer from 1 to 4; andn is an integer from 2 to 5; and physiologically acceptable salts and solvates (e.g. hydrates) thereof.The compounds have potent and selective vasoconstrictor activity and are indicated as useful for the treatment of migraine. They may be formulated as pharmaceutical compositions with pharmaceutically acceptable carriers or excipients for administration by any convenient route.Various methods for the preparation of the compounds (I) are disclosed.