Synthesis of substituted dihydropyridines by reacting ethoxymethylidenemalonate with malonic acid N-arylamidoesters

Resumo

Reactions of ethoxymethylidenemalonate with malonic acid N-arylamidoesters in the presence of triethylamine afforded diethyl 1-aryl-6-hydroxy-2-oxo-1,2-dihydropyridine-3,5-dicarboxylates via the cyclization of Michael adducts. In the presence of sodium ethoxide the formed adducts may be also involved into simultaneous retro-Michael reaction leading to the formation of ethyl 1-aryl-5-arylcarbamoyl-6-hydroxy-2-oxo-1,2-dihydropyridine-3-carboxylates. Direction of heterocyclization or retro-Michael reaction is determined by the acidity of the hydrogen atoms of adducts and basicity of catalyst.