(z)-type Nox Methylene The Neonicotinoid Tetrahydropyrimidin Synthesis And Insecticidal Activity

In order to search the introduction compounds for neonicotinoid insecticides, we have modified commercialized nitenpyram in this paper. Two series of novel nitromethylene neonicotinoid insecticides containing a cis-Configuration fixed by tetrahydropyrimidine with optical activity N-(α-substituted)-methyl acetate or N-(substituent)-benzoyl amide: (I) S-(+)-2-[(4Z)-4-[[(6-chloro-3-pyridinyl)methyl]ethylamino]-3-methyl-5-nitro-1,2,3,6- tetrahydropyrimidin-1-yl]-substituted acid methyl ester; (II) N-(substituent)-benzoyl amide: and N-[(4Z)-4-[[(6-chloro-3-pyridinyl)methyl]ethylamino]-3-methyl-5-nitro-1,2,3,6-tetra-hydropyrimidin-1-yl]- substituted benzamide were prepared. The structural formulas of compounds (I) and (II) are as follows respectively:Complete assignments have been achieved for the title compounds by elemental analysis, ~1H NMR, MS and IR. Meanwhile, their physic-chemical properties, spectrum properties, reaction conditions and synthetic methods were analyzed and discussed as well.The preliminary biological activities tests of the series target compounds were finished in bioassay department, Branch of National Pesticide R&D South Center of Hangzhou. The results indicated that some target compounds of (I) and (II) series have good insecticidal activities against Nilaparvata legen at 500mg/L. Especially, the compound Ih afforded the best in vitro inhibitory activity, and had 100% mortality 20 mg/L.In order to investigate the relationships between the structures and properties of the title compounds, some single crystals of compounds (I) were cultured and confirmed by X-ray diffraction analyses. To further explore the structural requirement for activity improvement and better selectivity, some target compounds were studied for their binding activity into the nicotinic acetylcholine receptors (nAChRs) by (Gaussian 03,Gaussian View,Accelrys DS visualizer 2.5 and AutoDock 4.0 ) molecular docking simulations. The results clearly indicated that the length and flexibility of the substituent group atα-position had major impacts on the biological activities of the designed analogues, which is more important for our team to discover new introduction compounds with broad-spectrum and high insecticidal activity.