Butkiewicz K, Jakubowski W
Pol J Pharmacol Pharm. 1978 Sep-Oct;30(5):695-705.
Polarographic reduction of the title compounds in mixtures of Britton-Robinson buffers and methanol (1:1) or DMF (3:1) for compound 10 at the pH range of 2.8--11.3 is described. In strongly acid medium the compounds were reduced in two diffusion governed waves corresponding to the consecutive reduction of NO2-group (6-electron wave) and pyrimidine ring (2-electron wave) to amine and dihydropyrimidine, respectively; with increasing pH the second wave became, however, much worse shaped. In alkaline medium a third wave appeared, the limiting current of which corresponded to a 2-electron process; the wave corresponds probably to the further reduction of pyrimidine ring to tetrahydroderivative. Mechanism of the reduction of the title compounds has been suggested and discussed.
描述了在Britton-Robinson缓冲液与甲醇(1:1)或二甲基甲酰胺(3:1)(用于化合物10)的混合物中,在2.8 - 11.3的pH范围内对标题化合物进行极谱还原的情况。在强酸性介质中,这些化合物在两个受扩散控制的波中被还原,分别对应于NO₂基团(6电子波)和嘧啶环(2电子波)连续还原为胺和二氢嘧啶;然而,随着pH值的增加,第二个波的形状变得更差。在碱性介质中出现了第三个波,其极限电流对应于一个2电子过程;该波可能对应于嘧啶环进一步还原为四氢衍生物。已提出并讨论了标题化合物的还原机理。