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 alpha- or beta-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. (c) 2007 Elsevier B.V. All rights reserved.