Reaction of 3-formylchromones with aromatic amino carboxylic acids

2-Alkoxy-3-(arylaminomethylene) and 3-(aryliminomethyl)chromones were prepa red by acid catalyzed reaction of 3-formylchromones with aromatic amino car boxylic acids in alcoholic reaction media. The results of the kinetic study have confirmed that 3-(aryliminomethyl)chromones are formed from 2-alkoxy- 3-(arylaminomethylene)chroman-4-ones. The dependence of the reaction rate o n reactant structure, the reaction media and the concentration of catalyst has been studied. In contrast to the alcoholic media reaction, the same rea ction in dry aprotic reaction media yielded only 2-hydroxy-3-(arylaminometh ylene)chroman-4-ones. No 3-(aryliminomethyl)chromones were isolated in that case. (C) 2001 Elsevier Science Ltd. All rights reserved.