Synthesis, Hydrolytic Stability And Bioassay Of Azabridged Neonicotinoid Compounds Containing Oxyamine And Hydrazide Group

Neonicotinoids played a key role in protecting crops around the world. Due to overuse of neonicotinoids, the growing resistance and high bee-toxicity have restricted the development of neonicotinoids. Based on neonicotinoid discovered in our group which have excellent activity and poor hydrolytic stability, oxyamine and amide group were introduced to the leading compound in order to improve its activity against Lepidopteran pests and enhance its hydrolytic stability. Forty novel azabridged neonicotinoid compounds containing oxyamine and amide group were designed and synthesized, whose structures were confirmed by’H NMR,13C NMR and high resolution mass spectroscopy (HRMS).The insecticidal activities of all synthesized compounds were tested against three representative insects including cowpea aphid (AphiscraccivoraKoch), brown planthopper (Nilaparvata lugens) and armyworm (Mythimna separata). Bioassays showed that two series of compounds exhibited excellent activities against cowpea aphid and brown planthopper. Especially, part of target compounds displayed 100% mortality against brown planthopper at 4 mg/L. Hydrazide azabridged neonicotinoid compounds showed high activity against both cowpea aphid and armyworm than oxyamine azabridged neonicotinoid compounds. Compound 4-3 displayed 100% mortality against armyworm at 20 mg/L.Hydrolytic stability test of the target compounds indicated that oxyamine azabridged neonicotinoid compounds have higher hydrolytic stability than the leading compound. Hydrolytic stability of oxyamine azabridged neonicotinoid has been improved significantly in comparion to imidacloprid, which is worthy being further researched.