One-pot synthesis of difluoromethyl-containing dihydropyrimidinones catalyzed by Yb(PFO)3 under solvent and dehydrating agent free conditions

The difluoromethyl-containing Biginelli dihydropyrimidinone derivatives were synthesized by a one-pot cyclocondensation of ethyl 4,4-difluoroacetoacetate, urea, and a variety of aldehydes in the presence of 5 mol% ytterbium perfluorooctanoate [Yb(PFO)3] under solvent and dehydrating agent free conditions. The comparison of reaction conditions and products was made among the different 1,3-dicarbonyl substrates (ethyl acetoacetate, ethyl 4,4-difluoroacetoacetate and ethyl 4,4,4-trifluoroacetoacetate) for the Biginelli reaction.