Basic ionic liquid-catalyzed multicomponent synthesis of tetrahydrobenzo[b]pyrans and pyrano[c]chromenes

Triethylenetetraammonium trifluoroacetate-catalyzed condensation of benzaldehydes, malononitrile and cyclic 1,3-dioxo compounds in aqueous medium affords the corresponding fused 2-amino-4-aryl-3-cyanopyrans.