Sayed Abdelwahed R, Wiggins Jeffrey S
School of Polymer Science and Engineering, The University of Southern Mississippi, Hattiesburg, Mississippi, 39406, Unites States.
Department of Chemistry, Faculty of Science, Beni-Suef University, Beni-Suef, 62514, Egypt.
Curr Org Synth. 2025;22(3):353-360. doi: 10.2174/0115701794287942240614070341.
Thiadiazoles exhibit a variety of biological activities, including antimicrobial, antiviral, antituberculosis, carbonic anhydrase inhibitor, antitrypanosomal agent, and anticonvulsant properties.
The new polymers are made in two distinct stages. The first stage is to prepare the starting material bis-(methyl-2-arylidenehydrazone-carbodithioates) via a condensation reaction between methyl-hydrazinecarbodithioate and dicarbonyl compounds in suitable solvent as isopropyl alcohol. The second stage for the synthesis of the final products poly(1,3,4-thiadiazoles) derivatives is the suitable bis-hydrazonoyl chloride reacted with an equal molar ratio of bis-(methyl- 2-arylidenehy-drazonecarbodithioates) in dimethyl sulfoxide, with triethylamine and reflux until the methanethiol gas stopped evolving. FT-IR (Fourier transform infrared spectroscopy), NMR (Nuclear magnetic resonance), and thermal investigation were used to identify and characterize the final products.
This work effectively synthesized new derivatives of poly(1,3,4-thiadiazoles) in good yields via the reaction of bis-hydrazonoyl dichlorides with bis-(methyl-2-arylidenehydrazonecarbodithioates). Two routes can be used to explain how the final poly(1,3,4-thiadiazoles) compounds are formed. The first route can be explained by nucleophile substitution of thiolate of bis(methyl-2-arylidenehydrazonecarbodithioates) to the chlorinated carbon of bis-hydrazonoyl dichlorides, followed by removal of HCl (hydrochloric acid) to provide an intermediate (S-alkylated). This intermediate at once leads to an intramolecular cyclo-polycondensation by the exclusion of methanethiol gas to produce our ending products poly(1,3,4-thiadiazoles). The second route concluded [3+2] cycloaddition of 1,3-dipolar cycloadditions of nitrilimines (generated by treatment of bis-hydrazonoyl dichlorides with triethylamine) to thione (C=S) followed by removal of methanethiol to give poly(1,3,4-thiadiazoles) as depicted in schematic diagram.
In this article, we reported an efficient method for the synthesis of the novel poly(1,3,4-thiadiazoles) from the reaction of bis-(methyl-2-arylidenehydrazonecarbodithioates) with bis-hydrazonoyl halides.
噻二唑具有多种生物活性，包括抗菌、抗病毒、抗结核、碳酸酐酶抑制、抗锥虫和抗惊厥特性。
新型聚合物分两个不同阶段制备。第一阶段是通过甲基肼基二硫代甲酸酯与二羰基化合物在合适溶剂（如异丙醇）中发生缩合反应，制备起始原料双 -（甲基 - 2 - 亚芳基腙 - 二硫代羧酸酯）。合成最终产物聚（1,3,4 - 噻二唑）衍生物的第二阶段是将合适的双肼基甲酰氯与等摩尔比的双 -（甲基 - 2 - 亚芳基腙 - 二硫代羧酸酯）在二甲基亚砜中反应，并加入三乙胺并回流，直到甲硫醇气体不再逸出。使用傅里叶变换红外光谱（FT - IR）、核磁共振（NMR）和热分析来鉴定和表征最终产物。
这项工作通过双肼基甲酰二氯与双 -（甲基 - 2 - 亚芳基腙 - 二硫代羧酸酯）的反应，以良好的产率有效合成了聚（1,3,4 - 噻二唑）的新衍生物。可以用两条路线来解释最终的聚（1,3,4 - 噻二唑）化合物是如何形成的。第一条路线可以解释为双 -（甲基 - 2 - 亚芳基腙 - 二硫代羧酸酯）的硫醇盐对双肼基甲酰二氯的氯化碳进行亲核取代，随后除去氯化氢（盐酸）以提供中间体（S - 烷基化产物）。该中间体立即通过排除甲硫醇气体导致分子内环化缩聚，从而生成最终产物聚（1,3,4 - 噻二唑）。第二条路线推断由双肼基甲酰二氯与三乙胺反应生成的腈亚胺发生[3 + 2]环加成到硫酮（C = S）上，随后除去甲硫醇得到聚（1,3,4 - 噻二唑），如示意图所示。
在本文中，我们报道了一种由双 -（甲基 - 2 - 亚芳基腙 - 二硫代羧酸酯）与双肼基卤化物反应合成新型聚（1,3,4 - 噻二唑）的有效方法。
