Pyridoindole derivatives and processes for preparation thereof

摘要

Compounds of the formula: <IMAGE> wherein R1 is hydrogen, lower alkyl or lower alkenyl, R2 is hydrogen, lower alkyl, or halogen, R3 is imidazolyl or pyridyl, each of which may have suitable substituents, and R4 is hydrogen, lower alkyl, lower alkenyl or hydroxy (lower) alkyl and R5 is hydrogen, hydroxy, or alkanoyloxy, or R4 and R5 are linked together to form an additional bond or novel pyridoindole derivatives which are useful as potent in selective antagonists of 5-HT receptors.