One-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones using CuBr2 as catalyst.
A simple, efficient procedure and improved conditions have been found to carry out the Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives. This synthesis was performed using CuBr2 as the catalyst in ethanol solution. The optimum conditions were as follows: the molar ratio of aldehyde to alpha,beta-diketone to urea or thiourea is 1:1:1:0.5, the molar ratio of catalyst to aldehyde is 25%, and the reaction time is 4 h. Under the above conditions, the highest yield of dihydropyrimidinones was up to 95%. Compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields and short reaction times.
Zhou
Haixia
H
Department of Chemistry, Liaoning University of Petroleum and Chemical Technology, Fushun, Liaoning, PR China.
He
Miao
M
Liu
Chunsheng
C
Jiang
Heng
H
Luo
Genxiang
G
D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D000431:Ethanol; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry
D001965:Bromides; D011744:Pyrimidinones; C408079:cupric bromide; D000431:Ethanol; D003300:Copper