An efficient synthesis of 3,4-dihydropyrimidin-2(1H)-one and 5,6-diphenylpyrimidine derivatives under solvent-free and base conditions

An efficient and convenient Biginelli-like reaction one-pot synthesis of a series of 4-aryl-5,6-diphenyl-3,4-dihydropyrimidin-2(1H)-one and 4-aryl-5,6-diphenylpyrimidine derivatives under solvent-free conditions from the reaction of aromatic aldehydes, 1,2-diphenylethanone, urea, guanidine carbonate or acetamidine hydrochloride has been reported. This methodology has the advantages of short reaction time, mild reaction conditions, easy work-up and environmental friendliness. Moreover, 4-aryl-5,6-diphenylpyrimidine derivatives were first reported in this process. The structures of the title compounds were further determined by X-ray diffraction. More importantly, different from general Biginelli reaction, this reported method was carried out under base conditions.