An unexpected triethylbenzylammonium chloride catalyzed ring opening of 2-pyrones in the synthesis of 1-arylbenzo[f]quinoline-2-carboxamide derivatives in aqueous media

Reaction of N-arylidenenaphthalen-2-amine and 4-hydroxy-6-methylpyran-2-one in aqueous media catalyzed by triethylbenzylammonium chloride (TEBAC) at 90 degrees C unexpectedly gave a pyrone ring-opening product 1-aryl-1,4-dihydro-3-[(E)-2-hydroxyprop-1-enyl]-N-(naphthalene-2-yl)benzo[f]quinoline-2-carboxamide. Modification of the reaction protocol resulted in a three-component reaction among N-arylidenenaphthalen-2-amine, 4-hydroxy-6-methylpyran-2-one and naphthalen-2-amine.