An efficient method for the synthesis of pyrano[3,2-c]quinoline-4,5-dione derivatives via iodine promoted intramolecular cyclization of 1-methyl-3-cinnamoyl-4-hydroxyquinolin-2-one, synthesized from aldol condensation of 1-methyl-3-acetyl-4-hydroxyquinolin-2-one with aromatic aldehydes in the presence of pyridine and PEG-400 under ultrasound irradiation, has been described. This method offers the advantages of a green approach, easy work-up, mild conditions and good yields.

No abstract