Clean synthesis in water: uncatalysed preparation of ylidenemalononitriles

A simple, efficient and environment-friendly procedure is developed for the condensation of malononitrile with aromatic, heteroaromatic and aliphatic aldehydes in water. The ylidenemalononitriles 3 are synthesised in high yields (84-98%) and selectivities (87-98%) in distilled water at 65 degrees C for 1 h, avoiding the addition of any catalyst.