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A new series of tetrahydropyrido [4,3-d]dihydropyrimidine-2-thiones (3a-3x) were designed and synthesized. Their structures were confirmed by 1 H NMR, IR, MS and elemental analysis, and the conformation of compound 3j was confirmed by X-ray diffraction. Preliminary bioassays indicated that most of the target compounds presented good antiproliferative activities against leukemic K562 cells, ovarian cancer HO-8910 cells and liver cancer SMMC-7721 cells in vitro. Among them the compounds 3i and 3m afford the best activity, the IC 50 of them were 3.22 and 3.65 μg/mL against leukemic K562 cells, respectively, which were lower than the anticancer drug of clinical practice 5-FU (IC 50 ＝8.56 μg/mL). Preliminary mechanism of action studies revealed that compound 3i caused DNA fragmentation and activated caspase-3/7 in leukemic K562 cells.

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 100 mg/L, whereas the compounds 3b and 3d afforded the best in vitro inhibitory activities that had ≥ 90% mortality at 20 mg/L.

All synthesized compounds show good insecticidal activity against Nilaparvata lugens.