H3PW12O40 as an efficient catalyst for one-pot-tricomponent synthesis of chro meno[4,3-b]quinolones under microwave irradiation

Some chromene[4,3-b]quinoline derivatives were synthesized in a three components one-pot reaction of 1,3-cyclohexadione,arylaldehydes and 4-aminocoumarin under microwave irradiation in the solventless system using a heteropolyacid catalyst,H3PW12O40in 80-95% yields and high rates.The shorter reaction times, one-pot, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the two step method. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.