A series of novel phenyl methoxyacrylate derivatives containing a 2-alkenylthiopyrimidine substructure were designed, synthesized, and evaluated in terms of acaricidal activity. The structures of the title compounds were identified by 1H NMR, 13C NMR and high-resolution mass spectra (HRMS). Compound (E)-methyl 2-(2-((2-(3,3-dichloroallylthio)-6-(trifluoromethyl)pyrimidin-4-yloxy)methyl)phenyl)-3-methoxyacr-ylate (4j) exhibited significant acaricidal activity against Tetranychus cinnabarinus (T. cinnabarinus) in greenhouse tests possessing nearly twice the larvicidal and ovicidal activity compared to fluacrypyrim. Furthermore, the results of the field trials demonstrated that compound 4j could effectively control Panonychuscitri with long-lasting persistence and rapid action. The toxicology data in terms of LD50 value confirmed that compound 4j has a relatively low acute toxicity to mammals, birds, and honeybees.
Keywords: acaricidal activity; phenyl methoxyacrylates; structure activity relationships; synthesis; thioether.