An Efficient one-pot Biginelli condensation of aliphatic aldehydes catalyzed by zinc bromide under solvent-free conditions.

Zinc bromide catalyzes the three component condensation reaction of an aldehyde, urea, and beta-ketoester or beta-diketone under solvent-free conditions to afford the corresponding dihydropyrimidinones (DHPMs) with moderate to high yields in short reaction time. The present method is very effective for the Biginelli condensation of aliphatic aldehydes.