Divergent sequential reactions of β-(2-aminophenyl)-α,β-ynones with nitrogen nucleophiles

beta-(2-An- nophenyl)-alpha,beta-ynones readily react with nitrogen nucleophiles to give three major types of products, depending on reaction conditions and variation in the nucleophiles. The reaction may lead to simple 1,2-nucleophilic adducts or, at higher temperatures, to a divergent sequential cyclisation giving rise to 2-aryl-4-aminoquinolines by reaction with amines, or to substituted 2-aryl or 2-alkyl-4-alkylidene quinazolines by reaction with amidines. The latter could also be synthesised by reaction of beta-(2-aminophenyl)-alpha,beta-ynones with iminochlorides. (C) 2004 Elsevier Ltd. All rights reserved.