Indolopyridines with a hetero atom at a position of fusion. 6. Electrophilic substitution in indolo[2,1-a]isoquinoline

Nitration, halogenation, azo coupling, aminomethylation, hydroxymethylation, and acylation reactions of indolo[2,1-a]isoquinoline in a neutral or weakly acid medium gave derivatives at the C₍₁₁₎ position (the pyrrole ring). Using nitrosation as an example, it was shown that electrophilic substitution at the benzene ring of the indole fragment can occur in a strongly acid medium.For Communication 5 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 83–89, January, 1994.