Azine-hydrazone Tautomerism of Thiazolylazo Pyridine Compound: Synthesis, Structural Determination, and Biological Activities
作者:Nutchanikan Phiromphu、Songwut Suramitr、Ratanon Chotima、Bussaba Boonseng、Apisit Songsasen、Akkharadet Piyasaengthong
DOI:10.1016/j.molstruc.2020.129658
日期:2021.4
compared to the structure in the solution determined by NMR. Based on the DFT quantum calculations, the result suggested that the most stable form of compound 1 was in the hydrazone-keto-keto (HYD-1) form with the lowest total energy. However, HYD-1 can tautomerize to the azine form (AZINE-1) in the solution as observed by the NMR analysis. The equilibrium of these two isomeric forms was also studied by UV-vis
摘要 通过低温重氮化和偶联反应合成了吖嗪-腙互变异构体1, (Z)-3-(2-(thiazol-2-yl)hydrazineylidene)pyridine-2,6(1H,3H)-dione。 . 通过单晶X射线衍射分析其针状晶体结构。从单晶分析获得的固态化合物1的分子结构与NMR确定的溶液中的结构相比呈不同的异构形式。基于 DFT 量子计算,结果表明化合物 1 的最稳定形式是腙-酮-酮 (HYD-1) 形式,总能量最低。然而,如 NMR 分析所观察到的,HYD-1 可以互变异构为溶液中的吖嗪形式 (AZINE-1)。这两种异构形式的平衡也通过紫外-可见光谱在不同的溶剂和 pH 值中进行了研究。吸收光谱显示化合物 1 随着 pH 值的增加而发生红移,并且两种异构体的百分比在 pH 值 5.8 时相等。此外,通过使用这些胃蛋白酶和木瓜蛋白酶分析之一研究了化合物 1 的生物活性。结果表明,化合物