Design, synthesis, and insecticidal/acaricidal evaluation of novel pyrimidinamine derivatives containing phenyloxazole moiety

A series of novel pyrimidinamine derivatives containing phenyloxazole moiety were designed and synthesized, and their structures were characterized by 1 H NMR, MS, and elemental analyses. The bioassay results displayed that some compounds exhibited remarkable insecticidal activities against Aphis fabae and Tetranychus cinnabarinus . Especially, 5-chloro-6-ethyl-2-methyl- N -((2-( p -tolyl)oxazol-4-yl)methyl)pyrimidin-4-amine ( 9o ) showed potent activity against A. fabae , superior to that of the commercial insecticide, imidacloprid. In addition, 5-chloro-6-ethyl-2-methyl- N -((2-(4-(trifluoromethyl)phenyl)oxazol-4-yl)methyl)pyrimidin-4-amine ( 9r ) showed potent activities against T. cinnabarinus , inferior to that of the commercial insecticide spirotetramat. The structure–activity relationship study for the target compounds was also discussed.