Cu(II)-Schiff base/SBA-15 as an efficient catalyst for synthesis of chromeno [4′,3′-b]pyrano[6,5-b]quinoline derivatives

Some chromeno[4′,3′-b]pyrano[6,5-b]quinoline derivatives were synthesized by condensation of 2-amino-4-aryl-3-cyano-5-oxo-4H, 5H -pyrano-[3,2-c] chromenes and 1,3-cyclohexanedione in an environmentally benign and efficient method by Cu(II)-Schiff base/SBA-15 as an environmentally friendly heterogeneous and recyclable catalyst under solvent-free conditions in high yields and rates. These kinds of catalysts are built from mesoporous silica SBA-15 which was covalently anchored with Cu(II) Schiff base complex. The shorter reaction times, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the last one. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.