Design, Synthesis And Insecticidal Activity Of New1,1-dichloropropene Derivatives

The resistance of insecticides is a worldwide problem. Discovering insecticides with a novel mechanism is an important way to deal with the problem. Pyridalyl, a comericial insecticide, controls Lepidopteran pests efficiently. It shows no cross-resistance with existing insecticides and low toxicity towards non-target organisms. In this thesis, our research was mainly focused on design and synthesis of new pyridalyl analogues with structural diversity so as to find compounds with high insecticidal activities and new structures. The detailed contents are as follows:1. This thesis introduced the discovery of Pyridalyl and structural modifications in recent literature reports.2. By structural modifications of Pyridalyl, we designed, and synthesized five series of1,1-dichloropropene derivatives. All of the new compounds have been characterized by NMR, HRMS, and the structures of two compounds with high insecticidal activities have been further confirmed by X-ray crystallography.3. The main strategy of structural modifications is as follows:(1) Replacing the pyridine moiety of Pyridalyl with other heterocycles might produce new lead compounds with higher insecticidal activities, so we designed and synthesized a series of1,1-dichloropropene derivatives containing structurally diverse heterocycles such as pyridines, pyrimidines, pyridazines, and benzothaizoles;(2) By introducing the carbamate moiety to the bridge of Pyridalyl, new1,1-dichloropropene derivatives have been synthsized;(3) By introducing the cyclopropane to the bridge of Pyridalyl, new1,1-dichloropropene derivatives have been synthesized;(4) Based on the principle of combination of bioactive substructure, we synthesized two series of diamides compounds by introducing the1,1-dichloropropene moiety to the active moiety of Chlorantraniliprole and Benzoylphenal azole;4. The insecticidal activities of most synthesized compounds were tested in Zhejiang Chemical Industry Research Institute. The LC50values were tested in Nanjing Agriculture University. The results showed that compounds Ⅰ3and Ⅰ26showed high insecticidal activities. Among the four tested insects, Ⅰ3showed comparable insecticidal activities with Pyridalyl against Bollworms and Prodenia litura, while I26showed comparable insecticidal activities with Pyridalyl against Bollworms and Diamondback Moths. Further field trial indicated that Ⅰ26can produce much better 14-day control effect against diamondback moths and longer duration of efficacy than Pyridalyl, indicating its potential of further development as a new insecticide for the control of lepidoptera insects. By introducing the carbamate moiety to the bridge of Pyridalyl, most compounds showed good activities against armyworms at the concentration of50ppm; by introducing the cyclopropane to the bridge of Pyridalyl, compounds Ⅲ1and Ⅲ2showed excellent activities against armyworm at the low dose of10ppm; introducing the1,1-dichloropropene moiety to the active moiety of Chlorantraniliprole and Benzoylphenal azole, compounds Ⅳ4, Ⅳ5, Ⅳ6, Ⅳ8, Ⅳ13, Ⅳ15, Ⅳ16showed100%larvicidal activity agaist armyworm at10ppm, theses compounds also showed good potential value for further study.5. We summarized the SAR (structure-activty-relationship) of all synthesized compounds, showing important direction for further study of1,1-dichloropropene derivatives.