A one-pot three-component Biginelli-like reaction of enaminones, aldehydes with urea/thiourea in the presence of 2-pyrrolidonium bisulphate as an acidic ionicliquidcatalyst 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.
Chemo-/regioselective synthesis of 6-unsubstituted dihydropyrimidinones, 1,3-thiazines and chromones via novel variants of Biginelli reaction
作者:Jie-Ping Wan、Yuan-Jiang Pan
DOI:10.1039/b901112a
日期:——
A novel and facile cascade Biginelli-like assembly employing enaminone, aldehyde and urea/thiourea has been developed, which provides a highly chemo- and regioselective synthesis of new dihydropyrimidinones, 1,3-thiazines and chromones by altering particular functional groups in the reactants.
Phenylphosphinic acid is found to catalyze the three-component condensation of an aldehyde, enaminone, and urea or thiourea to afford the corresponding 6-unsubstituted dihydropyrimidinones in high to excellent yields. This methodology is simple and fast synthetic route for the preparation of interesting class of heterocycles.