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

Abstract

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.

Keywords:

• tetrahydro-4H-pyrano [3,2-c]pyridine-3-carbonitriles
• green media
• diammonium hydrogen phosphate
• piperidine
• ring closure
• atom-economy
• condensation reaction

Acknowledgements

Saeed Balalaie is thankful to Alexander von Humboldt Foundation for research fellowship. We are also grateful to Prof. R. Gleiter for his invaluable comments. We also thank Kimia Exir Company for financial support and donation of chemicals and Tofigh Daru Research & Engineering Co. for kind cooperation.