Muataz J. Functionalized derivatives of 3,4-dihydropyrimidin-2(1H)-one and related 4,7-dihydroazolo[1,5-а]pyrimidines

For the first time the ability of N-methoxyurea as well as 1-(1-pyperidinylsulfonyl)acetones usage in the three-component Biginelli reaction is shown, that significantly widens the synthetic potential of the mentioned reaction. The interaction of 1-(1-pyperidinylsulfonyl)acetones, aromatic aldehydes and 3 amino-1,2,4-triazole in DMF result in 5-methyl-6-(1-pyperidinylsulfonyl)-4,7 dihydro[1,2,4]triazolopyrimidines formation, but when 4 nitrobenzaldehyde is explored the only product turn to be aromatic derivative, 5-methyl-7-(4-nitrophenyl)[1,2,4]triazolopyrimidine. The effective procedures are proposed for the synthesis of a number ethyl 4-aryl-3,4-dihydropyrimidin-2(1H)-one-5-carboxylates and diethyl 4-aryl-3,4-dihydropyrimidin-2(1H)-one-5,6-dicarboxylates, their 4,7-dihydroazolo[1,5 а]pyrimidine analogs as well as products of N-alkylation of the mentioned compounds, which are usable objects for an investigation of the reaction of the activated CH-position and C=C-double bond of the heterocyclic ring.