Primary thioamides are useful building blocks for drug and insecticide development, therefore an environmentally benign synthesis of primary thioamides is desired. This paper discloses an oxidative thiolysis for the selective transformation of nitriles into primary thioamides using elemental sulfur or thiuram in the presence of K₂S₂O₈ in DMF/H₂O. This practical method enables access to a wide range of synthetically and pharmaceutically useful primary thioamides. Advantages of this reaction include transition‐metal‐free and base‐free reaction conditions, use of an environmentally benign solvent (DMF/H₂O) system, the use of non‐toxic elemental sulfur or thiuram as the sulfur sources, and good functional groups tolerances with excellent selectivity. Furthermore, the insecticide Fipronil can also be converted to the corresponding thioamide and maintains excellent bioactivity against P. xylostella . The LC₅₀ value of Fipronil thioamide is 1.25 mg/L.

中文翻译：

---

腈选择性氧化硫解为初级硫代酰胺和杀虫剂的应用

伯硫代酰胺是药物和杀虫剂开发的有用组成部分，因此需要对环境有益的伯硫代酰胺合成。本文公开了一种氧化硫解，用于在DMF / H ₂ O中K ₂ S ₂ O ₈存在下，使用元素硫或秋兰姆，将腈选择性转化为伯硫酰胺。这种实用的方法能够获得广泛的合成和药学用途有用的伯硫代酰胺。该反应的优势包括无过渡金属和无碱反应条件，使用环境友好的溶剂（DMF / H ₂O）系统，使用无毒元素硫或秋兰姆作为硫源，并且具有良好的官能团耐受性和优异的选择性。此外，杀虫剂Fipronil也可以转化为相应的硫代酰胺，并保持了对小菜蛾的优异生物活性。Fipronil thioamide的LC ₅₀值为1.25 mg / L。