Synthesis and insecticidal activity of nitenpyram analogs with tetrahydropyrimidine fixed (z)-configuration

Two series of novel (Z)-nitenpyram analogs 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 3a, 3b, 3c, 3d were synthesized by introducing various amino acids benzyl ester or amino acids tetrahydrofurfur-2-yl ester into nitenpyram and forming a tetrahydropyrimidine ring to fix (Z)-configuration. The structures of the target compounds were characterized by 1HNMR, MS, IR, and elemental analysis. Preliminary bioassays against Nilaparvata lugens indicated that all the nitenpyram analogs exhibited good insecticidal activity at 100mg/L, whereas the compounds 3b and 3d afforded the best in vitro inhibitory activities that had90% mortality at 20mg/L.