Abstract

The 1,2,4-thiadiazole moiety is an important component of several biologically active compounds, and varying substituents on this aromatic ring is one of the possible methods to develop novel thiadiazole-based drugs for medicine. A key building block to this end, namely 3,5-diiodo-1,2,4-thiadiazole (1), has been synthesized and characterized in this work for the first time. 1 has exhibited high selectivity for the replacement of iodine atom at position C5 (carbon next to sulfur) in Sonogashira-type cross-coupling reactions with phenylacetylene. Therefore, 3-iodo-5-(phenylethynyl)-1,2,4-thiadiazole (4) or 3,5-bis(phenylethynyl)-1,2,4-thiadiazole (5) could be synthesized selectively depending on reaction conditions. All three novel molecules have been characterized by NMR, IR, Raman, mass, and UV spectroscopies, and their solid phase structures have been determined by single-crystal X-ray diffraction. 1 is expected to be a key starting material for producing thiadiazole-based therapeutic agents using cross-coupling reactions.

中文翻译：

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合成基于噻二唑的治疗剂：关键中间体3,5-二碘-1,2,4-噻二唑的合成，光谱研究，X射线分析和交叉偶联反应

摘要

1,2,4-噻二唑部分是几种生物活性化合物的重要组成部分，该芳香环上的不同取代基是开发新型基于噻二唑的药物的可能方法之一。为此目的，一个重要的组成部分，即3,5-二碘-1,2,4-噻二唑（1），已被首次合成和表征。图1显示了在与苯乙炔的Sonogashira型交叉偶联反应中C5位（碳原子旁边的硫原子）上碘原子置换的高选择性。因此，3-碘-5-（苯基乙炔基）-1,2,4-噻二唑（4）或3,5-双（苯基乙炔基）-1,2,4-噻二唑（5可以根据反应条件选择性地合成。这三种新分子均已通过NMR，IR，拉曼光谱，质谱和UV光谱进行了表征，其固相结构已通过单晶X射线衍射确定。预期1是使用交叉偶联反应生产噻二唑类治疗剂的关键原料。