Efficient and mild one-pot three-component reaction to synthesize pyrano[3,2-b]pyran derivatives in ionic liquid

A series of 2-amino-4-aryl-4H,8H-6-methyl-8-oxo-pyrano[3,2-b]pyran derivatives have been synthesized efficiently from aromatic aldehyde, malononitrile or cyanoacetate, and 5-hydroxy-2-methyl-4H-pyran-4-one via an one-pot three-component reaction catalyzed by Et3N in ionic liquid [bmim]BF4. The present approach offers the advantages of short reaction time, mild reaction conditions, high yields, convenient operation, and reuse of ionic liquid.