Direct synthesis of functional azaxanthones by using a domino three-component reaction.

ABSTRACT

NH aldimines, generated in situ from the corresponding aldehydes by reaction with ammonium acetate, serve as nitrogen nucleophiles in reactions with 3-(1-alkynyl)chromones and 3-cyanochromones that generate functionalized azaxanthones. These processes take place under mild conditions that do not require dry solvents. The products of the reactions described represent new chemical entities. We believe that the newly developed cascade process will serve as a potent method for the synthesis of N-heterocycles and in diversity-oriented synthesis.