Efficient synthesis of 2-amino-4-aryl-8-[(E)-arylmethylidene]-5, 6, 7, 8-4 H pyrano [3, 2-c]pyridine in green media.

An efficient,general, and atom-economic procedure for the synthesis of 2-amino-6 methyl-4-aryl-8-[(E)-arylmethylidene]-5, 6, 7, 8-4H-pyrano [3, 2-c]pyridine-3-carbonitriles has been developed by reaction of 3,5-bis[(E)-arylmethylidene]-tetrahydro-4(1H)-pyridinones with malononitrile. The reaction proceeds under green media (EtOH/H2O, 1:1) and in the presence of diammonium hydrogen phosphate (10%) or piperidine (10%) to afford pyranopyridines at room temperature with good high yields. [ABSTRACT FROM PUBLISHER]