In order to overcome the problem of pesticide resistance, it is necessary to discover novel pesticides with new mechanisms of action. Herein, a series of novel pyrimidin-4-amine derivatives containing trifluoroethyl sulfide moiety were designed and synthesized. Bioassays indicated that the title compounds synthesized possessed excellent acaricidal activity against Tetranychus urticae and fungicidal activity against Erysiphe graminis and Puccinia sorghi. Especially, the acaricidal activity of 5-chloro-6-(difluoromethyl)-N-(2-(2-fluoro-4-methyl-5-((2,2,2-trifluoroethyl)thio)phenoxy)ethyl)pyrimidin-4-amine (compound T4, LC₅₀ = 0.19 mg/L) against T. urticae was close to commercial acaricide cyenopyrafen, and the fungicidal activity of 5-chloro-6-(difluoromethyl)-2-methyl-N-(2-(3-((2,2,2-trifluoroethyl)thio)phenoxy)ethyl)pyrimidin-4-amine (compound T15, EC₅₀ = 1.32 mg/L) against P. sorghi. was superior to commercial fungicide tebuconazole. The synthesis and characterization of these compounds were given and the structure–activity relationships were discussed.

中文翻译：

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含三氟乙基硫醚部分的新型嘧啶-4-胺衍生物的设计、合成和杀虫活性

为了克服农药抗性问题，有必要发现具有新作用机制的新型农药。在此，设计并合成了一系列含有三氟乙基硫醚部分的新型嘧啶-4-胺衍生物。生物测定表明，合成的标题化合物对二斑叶螨具有良好的杀螨活性，对禾白粉菌和高粱柄锈菌具有良好的杀真菌活性。尤其是5-氯-6-(二氟甲基)-N-(2-(2-氟-4-甲基-5-((2,2,2-三氟乙基)硫基)苯氧基)乙基)嘧啶-的杀螨活性4-胺（化合物T4，LC ₅₀  = 0.19 mg/L）对二斑叶螨的杀真菌活性接近市售杀螨剂氰吡芬，且5-氯-6-(二氟甲基)-2-甲基-N-(2- (3-((2,2,2-三氟乙基)硫代)苯氧基)乙基)嘧啶-4-胺(化合物T15，EC ₅₀  = 1.32 mg/L)对抗高粱疫霉。优于市售杀菌剂戊唑醇。给出了这些化合物的合成和表征，并讨论了构效关系。