A Convenient Route to New Pyrrolo[1,2-c]pyrimidone, Thiazolo[3,4-c]pyrimidone and Pyrimido[4,5-d]pyridazine Derivatives
摘要:
The utility of versatile, readily accessible ethyl 6-bromomethyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (3) and ethyl 6-bromomethyl-2-oxo-4-phenyl-1,2-dihydropyrimidine-5-carboxylate (4) in the synthesis of some new pyrimidine, pyrimido[4,5-d]pyridazine, pyrrolo[1,2-c]pyrimidone and thiazolo[3,4-c]pyrimidone derivatives is reported.
Regioselective dehydrogenation of 3,4-dihydropyrimidin-2(1H)-ones mediated by ceric ammonium nitrate
摘要:
Ceric ammonium nitrate (CAN) has been explored for the regioselective oxidation of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs). Interestingly, we obtained ethyl 2,4-dioxo-6-phenyl-tetrahydropyrimidin-5-carboxylates as the major products during the oxidation of DHPMs by CAN/AcOH at 80 degrees C. The reaction afforded a mixture of products while employing CAN in organic solvents without additives. However, the regioselective dehydrogenated product, ethyl 6-methyl-4-aryl(alkyl)-pyrimidin-2(1H)-one-5-carboxylate was obtained by performing the reaction with NaHCO3. The single crystal X-ray crystallography of ethyl 6-methyl-4-(2-phenyl)-pyrimidin-2(1H)-one-5-carboxylate revealed that the oxidized product existed in amidic form rather than aromatized enol form of pyrimidines. The efficiency of the present protocol enabled the synthesis of structurally diverse pyrimidines in moderate to good yields under milder reaction conditions. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis and Antimicrobial Evaluation of Some New Pyrimidine Derivatives
作者:Ahmad M. Farag、Nabila A. Kheder、Yahia N. Mabkhot
DOI:10.3987/com-07-11286
日期:——
The utility of ethyl 6-methyl-2-oxo-4-phenyl-1,2-dihydropyrimidine-5-carboxylate (1) in the synthesis of some new pyrido[1,2-f]pyrimidine, pyrazolo-[3,4-b]pyrido[1,2-/]pyrimidine, 6-(4-substituted styryl)pyrimidine, pyrido[4,3-d]-pyrimidine, pynmido[5,4-d]pyridazine and substituted-6-(thien-2-yl)pyrimidine derivatives is reported. Antimicrobial evaluation of some selected examples from the synthesized