Experimental and theoretical investigations on the keto–enol tautomerism of 4-substituted 3-[1-methylpyrrol-2-yl)methyl]-4,5-dihydro-1H-1,2,4-triazol-5-one derivatives
作者:Monika Pitucha、Zbigniew Karczmarzyk、Waldemar Wysocki、Agnieszka A. Kaczor、Dariusz Matosiuk
DOI:10.1016/j.molstruc.2011.03.041
日期:2011.5
possessing the carbonylgroup. In the present study we use X-ray analysis, IR spectroscopy as well as quantum chemical calculation to address the keto–enol tautomerism of 4-substituted 3-[1-methylpyrrol-2-yl)methyl]-4,5-dihydro-1 H -1,2,4-triazol-5-one derivatives with antimicrobial activity. In the gas phase and in the crystalline state all the investigated molecules exist in the keto form while in the
摘要 酮-烯醇互变异构是决定具有羰基的化合物药理活性的关键现象。在本研究中,我们使用 X 射线分析、红外光谱以及量子化学计算来解决 4-取代 3-[1-甲基吡咯-2-基)甲基]-4,5-二氢- 1 H -1,2,4-triazol-5-one 衍生物,具有抗菌活性。在气相和结晶状态下,所有研究的分子都以酮形式存在,而在氯仿溶液中,观察到少量与酮形式平衡的烯醇形式。计算结果与在 KBr 中从 X 射线分析和红外光谱获得的实验数据非常一致,但不能证实互变异构平衡在氯仿溶液中转变为烯醇形式。
Synthesis and RP HPLC studies of biologically active semicarbazides and their cyclic analogues 1,2,4-triazol-3-ones
作者:Monika Pitucha、Joanna Matysiak、Bogdan Senczyna
DOI:10.1007/s00706-011-0715-z
日期:2012.4
The retention behaviour of semicarbazides and their cyclic analogues 1,2,4-triazol-3-ones, has been investigated by RP-8, RP-18 and IAM HPLC. The structures of new derivatives were proved by elemental analyses, IR, H-1 NMR and C-13 NMR spectroscopy. The compounds showed regular retention behaviour in three chromatographic systems; their log k values decreased linearly with the increasing concentration of an organic modifier in the mobile phase. The ratio of the intercept (log k (w)) to the slope of compounds is constant and the same for both groups of compounds on C18 and IAM stationary phases. Differences between log k (w) values from the octadecyl stationary phase of corresponding cyclic and linear derivatives are constant, and they are related to the mechanism of synthesis of 1,2,4-triazol-3-ones from linear substrate semicarbazides, which was confirmed by modelling studies. Good correlations between log k (w) parameters obtained by RP-8 or RP-18 and determined by the computational approach log P were found.