Formyl- or cyano- substituted indole derivatives having dopaminergic activity

Invention relates to novel 6,7,8,9-tetrahydro-3H-benz(e)indolamine derivatives and their therapeutic use. Novel compounds are of formulae (Ia) and (Ib): [Figure] wherein R1 and R2 are independently hydrogen, C1-6alkyl, C3-7cycloalkyl, -CH2-C3-7cycloalkyl, phenyl (optionally substituted with halogen or C1-6alkyl), thiophenyl (optionally substituted with halogen or C1-6alkyl) or phenyl-C1-6alkyl. The R3's and Y are independently hydrogen, -O-C1-6alkyl or C1-6alkyl; X is valence bond, CH2 or oxygen; and R4 and R5 are independently hydrogen, CHO or CN, provided that they both are not hydrogen. These compounds and derivatives thereof predominantly exhibit dopamine-receptor stimulating activity in mammals. They may therefore be used for treating mammals suffering from dopamine-generated central nervous system disorders. They can be useful for treating hyperprolactinemia, galactorrhea, amenorrhea, impotence, Parkinsonism, diabetes, acromegaly, hypertension and other central nervous system disorders which respond to dopamine-receptor stimulation.