Tungstate sulfuric acid catalyzed one-pot synthesis of a new class of aroylamido coumarins under solvent-free conditions

A one-pot synthesis of novel aroylamido coumarins from the reaction of 4-hydroxycoumarin with aryl glyoxals and benzamides in the presence of a catalytic amount of tungstate sulfuric acid (TSA) is described. The method is operationally simple and provides access to a variety of aroylamido coumarins in good yields.