Synthesis of 2-amino-4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinolin-5-one derivatives in water

A series of 2-amino-4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinolin-5-one derivatives were synthesized by the TEBA (triethylbenzyl ammonium chloride) catalyzed reaction of arylmethylidenemalononitriles or 3-aryl-2-cyano-1-acrylate with 4-hydroxy-1,2-dihydroquinolin-2-one in water at 90 degrees C. Compared with other synthetic methods, this method has the advantages of milder reaction conditions, high yields (87%similar to 96%) and environmentally benign procedure. The structures of the products were characterized by melting points, IR, H-1 NMR spectra and elemental analysis, and the structure of compond 3m was confirmed by X-ray diffraction analysis.