Synthesis, insecticidal activities and DFT study of pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif

Twenty six novel pyrimidin-4-amine derivatives containing the 1,2,4-oxadiazole motif were synthesized. Their chemical structures were confirmed by 1 H nuclear magnetic resonance (NMR), 13 C NMR, and highresolution mass spectrography. The insecticidal activity results indicated that some of them possessed excellent insecticidal activity (100%) against Mythimna separate , especially for compounds 6d, 6f, 6o, 6w, 6y and 6z . These compounds exhibited no activity against the insects Aphis medicagini and Tetranychus cinnabarinus . The structure-insecticidal activity relationships are discussed. Density functional theory analysis can potentially be used to design more active compounds. These results provide useful insecticide design information for further optimization.