Sodium ethylene diamine tetraacetate catalyzed synthesis of chromene derivatives via multi-component reactions at low catalyst loading

An efficient and practical protocol for the synthesis of chromenes derivatives catalyzed by a low-loading sodium ethylene diamine tetraacetate (2 mol%) as a catalyst via multicomponent reaction is reported. A wide range of aromatic aldehydes easily undergo condensations with malononitrile and 4-hydroxycoumarin (4-hydroxy-6-methyl-2-pyrone or dimedone) under mild conditions to afford the desired products of good purity in excellent yields. This protocol has several advantages, such as mild conditions, high yields, and an inexpensive catalyzed system.