Design,Synthesis And Biological Activity Study Of Dimethomorph Derivatives And Benzoylurea Derivatives

According to the reported structure-activity relationship,we synthesized 45 compounds of dimethomorph derivatives containing triazole group（I）and benzoylurea derivatives containing pyrimidine group（II）of 2 series based on the molecular design principle and method of fungicides and pesticides.The fungicidal activity of all the compounds was tested,and the insecticidal activity against Mythimna separate and Culex pipiens pallens of series II compounds was tested.These new compounds were identified by ’H NMR、13C NMR and HRMS.In the part one of the thesis,we design and synthesized 8 dimethomorph derivatives containing triazole group（I）.The results of bioassay showed that these compounds did not exhibit good fungicidal activity.Compound I-1 exhibited 71.4%inhibitory activity against Physalospora piricola and Ⅰ-4 showed 53.6%inhibitory activity against Sclerotinia sclerotiorum at 50 mg L^-1.The two compounds exhibited better fungicidal activity than dimethomorph and flumorph.In the part two of the thesis,we design and synthesized 37 benzoylurea derivatives containing pyrimidine group（II）.Compound II-3 exlhibited better fungicidal activities（Compound II-3 exhibited respectively 91.1%、89.5%and 62.5%inhibitory activity against Physalospora piricola、Rhizoctonia cerealis and Sclerotinia sclerotiorum）.Using compound Ⅱ-3 as a lead compound,we optimized compoundⅡ-10 which had specific fungicidal activity against Physalospora piricola,and compound Ⅱ-7、Ⅱ-19、Ⅱ-24and Ⅱ-27 which exhibited a broad fungicidal spectrum.Above all,compound Ⅱ-19 exhibited more than 60%inhibition rate against 14 kinds of fungus,which exhibited wider fungicidal spectrum than pyrimethanil.The insecticidal activities against Mythimna separata、Culex pipiens pallens were tested.The results of bioassay showed that these compounds did not exhibit good insecticidal activities against Mythimna separate,but some compounds exhibited excellent larvicidal activities against Culex pipiens pallens.In particular,compoundⅡ-2 had 100%morality against Culex pipiens pallens at 0.25 mg L^-1.Compounds Ⅱ-7 exhibited a broad insecticidal spectrum,and showed 100%morality against Mythimna separate at 200 mg L^-1.From the result of bioassay we knew that compound Ⅱ-3 and II-7 have fungicidal activity and insecticidal activity both.