Reactions of 4-Cyanobenzo[c]pyrylium Salts with Nitrogen-Containing Nucleophiles

The recyclization reactions of 4-cyanobenzo[c]pyrylium salts with ammonia, primary amines, and hydrazines have been studied. New derivatives of isoquinoline, benzo-2,3-diazepine, and pyrazolo-[ 5,4-c]isoquinoline have been obtained.