Design, synthesis, and insecticidal activity of novel neonicotinoid derivatives containing N-oxalyl groups

Two series of novel neonicotinoid derivatives containing N-oxalyl groups were designed and synthesized, and their structures were characterized by H-1 NMR spectroscopy, high-resolution mass spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The insecticidal activities of the new compounds were evaluated. The results of bioassays indicated that some of these title compounds exhibited excellent insecticidal activities. The insecticidal activities of compounds 13c, 13d, 13g, 13h, and 13i against bean aphids at 12.5 mg kg(-1) were 100%; the insecticidal activities against bean aphids of the derivative 13 c, 13d, 13g, 13h, and 14h were comparable to imidacloprid at 6.25 mg kg(-1). Surprisingly, the results indicated that the activity of ethyl 2-(3-((6-chloropyridin-3-yl)methyl)-2-(nitroimino)imidazolidin-1-yl)-2-oxoacetate (13b) against bean aphids at 6.25 mg kg(-1) was 96%, which was higher than the commercialized imidacloprid.