The rapid and green procedure for the Knoevenagel reaction between aromatic aldehydes and diethyl malonate was developed by using 1-butyl-3- methylimidazolium hydroxide, [Bmim]OH, as an efficient catalyst. The condensations showed good yields with a wide range of aromatic aldehydes in solvent-free condition and short reaction times. [Bmim]OH was easy to recover and could be reused several times without significant loss of catalytic activity. | An efficient [Bmim]oh catalysed the condensations of aromatic aldehydes and diethyl malonate
