Synthesis And Insecticidal Activities Of Novel Neonicotinoids Analogues Containing Imidazo [1,2-a] Pyridones And Spirocyclic Structures

Based on the structure of cis-cofigutation neonicotinoid, two series of new neonicotinoid analogues (total 42 compounds) with diverse Structures were designed and synthesized. All the synthesized compounds were confirmed by NMR, HRMS and IR spectroscopy.From the point of view of chemical diversity, a further derivation of aldehydes was investigated. A series of 1,2,3,4-tetrahydroimidazo pyridones derivatives(total 25 compounds) as novel neonicotinoid candidates were designed and synthesized by reactions of nitromethylene analogues and itaconic anhydride and the following esterification and amidation were carried out. Bioassays showed that the target compounds exhibited excellent insecticidal activities against cowpea aphids(Aphis craccivora) and brown planthopper(Nilaparvata lugens).. Compound IPPA166115 showed insecticidal activities on cowpea aphids with the mortality 40% at 4 mg/L. Some compounds exhibited insecticidal activities on brown planthopper with the mortality above 80% at 20 mg/L. While against armyworm (Pseudaletia separate Walker), most of the compounds had moderate activities. One of the compounds exhibited insecticidal activities on Tetranychus cinnabarinus with the mortality 95% at 500 mg/L.Combined the structure of spirocycle and neonicotinoids, a series of new neonicotinoid analogues (total 17 compounds) with imidazo[1,2-a]pyridones and spirocyclic structures were designed and synthesized. Bioassays showed that the some of the target compounds exhibited excellent insecticidal activities against armyworm and brown planthopper. But small changes in the structures lead to the insecticidal activity transformed from Homoptera to Lepidoptera pests. We verified the structure through the single crystal structure and found that ester group is more active reactive group than cyano when cyano and ester group exist at the same experimental conditions, and this competitive reaction has not been reported in the present literatures.