Abstract

One of the goals of green chemistry is to use environmentally friendly solvents or remove and reduce the volume of harmful spent solvents. In this study, a novel process for the synthesis of 5-substituted 1,3,4-oxadiazole-2-thiol derivatives was proposed via ultrasound-assisted reaction of aryl hydrazides with CS₂ (1:1 molar ratio) in some drops of DMF in the absence of basic or acidic catalysts. They were produced in good to excellent yields under easy workup and purification conditions. In order to prove the usefulness of the prepared compounds, their antioxidant, antibacterial, and antifungal potentials were screened by DPPH free radical scavenging, serial twofold microdilution and streak plate methods. Acceptable to significant inhibitory activities were observed with synthesized heterocycles. The results showed that 5-(4-fluorophenyl)-1,3,4-oxadiazole-2-thiol (3c) is an broad-spectrum antimicrobial agent. Many of them displayed remarkable antioxidant properties comparable to standard controls (ascorbic acid and α-tocopherol). Synthesized 1,3,4-oxadiazoles are also potent candidates to treat cancer, Parkinson, inflammatory, and diabetes diseases.

Graphic Abstract

Eighteen 5-substituted 1,3,4-oxadiazole-2-thiol derivatives as potent antimicrobial and antioxidant agents were prepared via a new, efficient and green procedure.

中文翻译：

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超声辅助、低溶剂、无酸/碱合成 5-取代 1,3,4-恶二唑-2-硫醇作为有效的抗菌剂和抗氧化剂。

 抽象的

绿色化学的目标之一是使用环境友好的溶剂或去除和减少有害的废溶剂的量。在本研究中，提出了一种合成 5-取代 1,3,4-恶二唑-2-硫醇衍生物的新工艺，通过芳基酰肼与 CS ₂ （摩尔比 1:1）在几滴水中进行超声辅助反应。 DMF 在没有碱性或酸性催化剂的情况下进行。它们在简单的后处理和纯化条件下以良好到优异的产率生产。为了证明所制备的化合物的实用性，通过DPPH自由基清除、连续双倍微量稀释和划线板方法筛选其抗氧化、抗菌和抗真菌潜力。用合成的杂环观察到显着的抑制活性是可接受的。结果表明，5-(4-氟苯基)-1,3,4-恶二唑-2-硫醇( 3c )是一种广谱抗菌剂。其中许多表现出与标准对照（抗坏血酸和α-生育酚）相当的显着抗氧化特性。合成的 1,3,4-恶二唑也是治疗癌症、帕金森病、炎症和糖尿病的有效候选药物。

 图文摘要

通过一种新的、高效的、绿色的工艺制备了 18 种作为有效抗菌剂和抗氧化剂的 5-取代 1,3,4-恶二唑-2-硫醇衍生物。