Treatment of several Ï-halogenoamides, derived from tryptamine, with powdered potassium hydroxide in 1,2-dimethoxyethane in the presence of 18-crown-6, resulted in intramolecular and/or bimolecular cyclization, depending on the length of the chain and dilution conditions, to give macrocyclic compounds. Some of them were converted by a Bischler-Napieralski reaction, followed or not by reduction, to new tetracyclic derivatives of β-carbolines.