Syntheses and Fungicidal Activities of Thiazole-5-carboxanilides Bearing Thioether Group

In an attempt to find leading thiazole carboxanilides exhibiting fungicidal activities, we designed and synthesized a new series of 2-sulfursubstituted thiazole carboxanilides via the reaction between 2-sulfur substituted thiazole carboxylic acid chlorides and substituted aniline. The fungicidal activities of the title compounds against Rhizoctonia solani were screened and the results were remarkable. The most potent compound 8i, N-2,6-dichloro-4-(trifluoromethyl)phenyl]-2-methylthio-4-(trifluoromethyl)thiazole-5-carboxamide, was identified. The fungicidal EC₅₀ of compound 8i against Rhizoctonia solani was 1.28 mg/L, being comparable to that of Thifluzamide. The results indicate that compound 8i can be considered as a lead compound for further research.