Synthesis of Pyrido[2,3-c]coumarin Derivatives by an Intramolecular Povarov Reaction

Fused pyrido[2,3- c ]coumarin derivatives were prepared by an intramolecular Povarov reaction of 2-(propagyloxy)benzaldehydes with 3-aminocoumarins in the presence of 10 mol% of triflic acid as a catalyst in refluxing acetonitrile. Among the advantages of this protocol are shorter reaction times, good yields, and the absence of the need for aqueous workup and chromatographic separation.