An efficient three-component domino synthesis of difluoromethyl-containing 1,4-dihydropyridines under solvent and catalyst free conditions

The difluoromethyl-containing Hantzsch 1,4-dihydropyridines were synthesized in good yields by a one-pot cyclocondensation of ethyl difluoroacetoacetate (EDFAA), a variety of aromatic aldehydes and ammonium acetate under solvent and catalyst free conditions. The comparison of reaction conditions and products was made among the different 1,3-carbonyl substrates (ethyl acetoacetate, ethyl difluoroacetoacetate and ethyl trifluoroacetoacetate) for the Hantzsch reaction.