Solvent-free condensations of ketones with malononitrile catalysed by methanesulfonic acid/morpholine system

The preparation of ylidenemalononitriles via Knoevenagel condensations of ketones with malononitrile under solvent-free conditions is described. Good yields and short reaction time are the features observed with methanesulfonic acid (MSA)/morpholine used as the catalyst. The wide applicability of the protocol is shown by the fact that not only unconjugated, but also aryl-alkyl ketones gave satisfactory yields.