A task specific basic ionic liquid, [bmIm]OH-promoted efficient, green and one-pot synthesis of tetrahydrobenzo[b]pyran derivatives

A basic ionic liquid, 1-butyl-3-methyl imidazolium hydroxide, [bmIm]OH has been used as an efficient catalyst for the synthesis of a variety of 4H-benzo[b]pyran derivatives by a one-pot three component condensation of aldehydes, cyclohexa-1,3-diones and malononitrile/ethyl cyano acetate at room temperature. The reactions are very fast (5-20 min), high yielding (85-98%) and do not require any organic solvent.