With the increasing evolution of pesticide resistance, pyrimidinamine derivatives are considered promising agricultural compounds because of their outstanding activity and their mode of action which is different from other fungicides. But diflumetorim, the commercial pyrimidinamine fungicide, is not effective in controlling corn rust (Puccinia sorghi). In this study, a series of pyrimidinamine derivatives were designed and synthesized using pyrimidifen as a template according to the bioisosterism. The new compounds showed excellent fungicidal activity. Among these compounds, (S)-5-chloro-6-(difluoromethyl)-2-methyl-N-(1-((5-(trifluoromethyl)pyridin- 2-yl)oxy)propan-2-yl)pyrimidin-4-amine, T33, had the best control effect on corn rust with EC₅₀ values of 0.60 mg/L, versus commercial fungicide tebuconazole (1.65 mg/L). The synthesis, characterization, and activity data of the compounds are presented in the text, and the structure-activity relationships are discussed.

Graphical Abstract

中文翻译：

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含吡啶-2-基氧基基团的嘧啶胺衍生物的设计、合成及杀菌活性

随着农药抗药性的不断演变，嘧啶胺衍生物因其突出的活性和不同于其他杀菌剂的作用方式而被认为是有前途的农用化合物。但商业嘧啶胺杀菌剂二氟嘧啶不能有效控制玉米锈病（Puccinia sorghi）。本研究以嘧啶胺为模板，根据生物电子等排现象，设计合成了一系列嘧啶胺类衍生物。新化合物表现出优异的杀真菌活性。在这些化合物中，(S)-5-氯-6-(二氟甲基)-2-甲基-N-(1-((5-(三氟甲基)吡啶-2-基)氧基)丙-2-基)嘧啶- 4-胺T33对玉米锈病的防治效果最好，EC ₅₀值为 0.60 mg/L，而商业杀菌剂戊唑醇 (1.65 mg/L)。文中介绍了化合物的合成、表征和活性数据，并讨论了构效关系。

图形概要