Design, synthesis, and insecticidal activity of pyrimidinamine derivatives containing 2-pyridinyloxy moiety

Aphis fabae is a widespread pest that has more than 200 hosts in the world, belongs to hemiptera, for stinging suction mouthparts, harm buds, young leaves, and flower buds. Pyrimidine derivatives have the advantages of insecticidal, bactericidal, herbicidal, regulating plant growth and other biological activities, and have a unique mechanism of action. Pyrimidinamine derivatives, one of pyrimidine derivatives, were reported as early as 1955, and all the world's major pesticide companies (Syngenta, Dow Yinon, Bayer, DuPont, and BASF) have carried out research studies, which had lasted for nearly 60 years. For example, commercial pyrimidine products such as flupyrimethanil (fungicide) and pyrimethanil (insecticidal and acaricidal agents) show excellent biological activity. So pyrimidinamine derivatives are considered promising agricultural compounds. In this study, a series of pyrimidinamine derivatives were designed and synthesized using pyrimidifen as a template according to bioisosterism. 5-chloro-N-(1-((3-chloro-5-(trifluoromethyl)pyridin-2-yl)oxy)-2-methylpropan-2-yl)- 6-ethylpyrimidin-4-amine, T23, had the best control effect on Aphis fabae with LC50 values of 1.46 mg/L, versus commercial insecticides spirotetramat and imidacloprid (2.45 and 0.53 mg/L). The synthesis, characterization, and activity data of the compounds are presented in the text, and the structure-activity relationships are discussed.