Synthesis And Insecticidal Activity Of Benzenesulfonamides

China has a large population and is also a big agricultural country.It is vital to ensure food security and maintain high and stable production of grain.Because of its high speed and difficulty in prevention and control,insect pests have always been a threat to crops from sowing to harvesting and are one of the major agricultural disasters in China.So far,there are many ways to prevent and control pests.Among them,pesticide application is still the most effective means to control pests.However,the large-scale application of pesticides has also caused many problems,such as the emergence of cross-resistance of existing pesticides,the single target of the target,and the increasing resistance of pests,based on the needs of ecological environmental protection and the development of pesticide resistance,the creation of new green pesticides has become more urgent.The discovery of new lead compound structure and novel target of action is an extremely important part of the creation of new pesticides.Our research group conducted in-depth and meticulous research on the insecticidal plant celastrus angulatus,celangulin V as a molecular probe,and its target protein V-ATPase H subunit was obtained by affinity chromatographyandothertechniques.Twosulfonamidecompounds:2-?4-chloro-5-?N-?4-ethoxyphenyl?sulfamoyl?-2-methylphenoxy?acetamide,2-?4-chloro-2-methyl-5-?N-?p-tolyl?sulfamoyl?phenoxy?acetamide with good activity were obtained by homologous modeling and virtual screening.,this project designed and synthesized these two compounds and used them as lead compounds,4-chloro-2-cresol,sodium4-hydroxybenzenesulfonate and sodium 2-chloro-5-hydroxybenzenesulfonate as starting materials,71 derivatives were designed and synthesized,the structures of the compounds were identified by 1H NMR and 13 C NMR,and their insecticidal activities were evaluated.The main results are as follows:1.Chemical synthesis:4-chloro-2-cresol as a raw material,through phenol hydroxyl etherification,aminolysis,hydrazinolysis,hydrolysis,benzene sulfonylation,sulfonyl amination and other synthetic steps,47 compounds including 3a-3l,4a-4l,5a-5k and 6a-6l were designed and synthesized;sodium 4-hydroxybenzenesulfonate and sodium2-chloro-5-hydroxybenzenesulfonate as starting materials,through phenolic hydroxyl groups etherification to propargyloxy,sulfonyl amination,26 compounds including 7a-7m and 8a-8m were designed and synthesized.The structures of the compounds were identified by nuclear magnetic spectroscopy,and after searched for in the literature,all of which were new compounds.2.Evaluation of insecticidal activity:The third instar larva of M.separata was used as the test insect,the celangulin V was used as the positive control,and acetone was used as the blank control.The insecticidal activity of the synthesized 73 compounds was evaluated,15 compounds?7a,7b,7d,7g,7h,7l,7m,8a,8b,8d,8e,8h,8k,8l,8m?with good insecticidal activity were found by active primary screening,rescreening and LC₅₀measurements further revealed seven high-activity compounds,including 7a,7g,7h,7m,8b,8h and 8m,with LC₅₀ values of 2.247 mg/mL,0.904 mg/mL,0.293 mg/mL,0.471mg/mL,0.707 mg/mL,3.464 mg/mL,0.985 mg/mL.Compared with the positive control celangulin V(LC₅₀ value of 23.901 mg/mL),the virulence of compounds 7a,8h,7g,8m,8b increased by about one order of magnitude;the virulence of compounds 7h,7m even increased two orders of magnitude.Among them,compound 7h has the best insecticidal activity.