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. © 1994 Plenum Publishing Corporation.