Three-component condensation of phenylglyoxal, alkyl acetoacetates or acetylacetone and urea proceeds smoothly, catalyzed by ZnCl2, to afford the corresponding new 3,4- dihydropyrimidinones. This reaction is also catalyzed by AlCl3:ZnCl2 (3:1) under microwave irradiation in solvent-free conditions. One-pot three-component condensation of dimethyl urea, acetylacetone or alkyl acetoacetate and phenylglyoxal catalyzed by ZnCl2 or AlCl3:ZnCl2 (3:1) yields new multisubstituted imidazoline-2-ones derivatives. Structures of products were studied by X-ray crystallographic data. The reaction of phenylglyoxal, urea and β-ketoesters in the presence of hydrochloric acid produces only 5-phenylhydantoins.
