ChemInform Abstract: Green, One-Pot, Solvent-Free Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles Using a Broensted Acidic Ionic Liquid as Novel and Reusable Catalyst.
AbstractA one-pot three-component Biginelli-like reaction of enaminones, aldehydes with urea/thiourea in the presence of 2-pyrrolidonium bisulphate as an acidic ionic liquid catalyst for the preparation of 6-unsubstituted dihydropyrimidinones is described. The excellent yield, short reaction time, simple procedure and avoidance of the use of organic solvents are some advantages of this method.