Basic ionic liquid as catalyst for the rapid and green synthesis of substituted 2-amino-2-chromenes in aqueous media

A basic functionalized ionic liquid, 1-butyl-3-methyl imidazolium hydroxide ([bmim]OH), catalyzed three-component condensation reaction of aromatic aldehydes, malononitrile and α- or β-naphthol proceeded rapidly in water at reflux to afford corresponding 2-amino-2-chromenes in high yields. The greener protocol was found to be fairly general and the aqueous reaction media was reused in subsequent reactions with consistent activity.