Synthesis and insecticidal evaluation of novel N-pyridylpyrazolecarboxamides containing an amino acid methyl ester and their analogues.

On the basis of the commercial insecticide chlorantraniliprole, a series of novel N-pyridylpyrazolecarboxamides containing an amino acid methyl ester and their analogues were designed and synthesized. Their chemical structures were established on the basis of corresponding (1) H NMR spectroscopy, (13)C NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. The insecticidal activities of the new compounds against oriental armyworm ( Mythimna separata ) and diamondback moth ( Plutella xylostella ) were evaluated. The results of bioassays indicated that most of the compounds showed moderate to high activities at the tested concentration, of which the compounds 6 containing a methyl acrylate substructure had excellent larvicidal activity; for example, 6a displayed 100% larvicidal activity against P. xylostella at the concentration of 0.005 mg/L, whereas the activities of both compounds 6g and 6h against M. separata were 100% at 2.5 mg/L. The calcium imaging technique experiment results showed that novel compound 6 could elevate the calcium concentration in the cytoplasm. Furthermore, this study also provided evidence that compound 6h activates inositol 1,4,5-trisphosphate (IP3) sensitive intracellular calcium release channels in the endoplasmic reticulum of Spodoptera exigua third-instar larva neurons.