The Design, Synthesis And Biological Activity Of New Oxadiazole Derivatives

In order to develop new bactericids containing oxadiazole structure,In this this work.Two new series of oxadiazole ethers containing pyridine structure were designed and and syntheised by using substituted benzoic acid,2-?chloromethyl?-3-methyl-4-?2,2,2-trifluoroethyl?as starting materials.The synthesized compounds were characterized by HRMS,¹H NMR,¹³C NMR and ¹⁹F NMR.The insecticidal activity of A series compounds against Plutella xylostella was tested by leaf-fed feeding method.The results showed that some compounds had certain insecticidal activity,compounds A₄,A₈ and A₁₀0 showed 100%at concentration of 100?g/mL.The bactericidal activity of the synthesaed compounds were evaluated by employing turbidity method and commercial thiodiazole copper and bismerthiazol as positive controls.The results showed that some of the synthesized conpounds displayed excellent bacterial activity.Such as the EC₅₀0 value of compound A₂₂2 was 34.3?g/mL against Ralstonia solanacearum and was superior to commercial thiodiazole copper(EC₅₀=107.5?g/mL).Some of the B series compounds were also showed excellent bacterial activity against Ralstonia solanacearum,Xanthomonas oryzae pv.Oryzae?Xoo?,and Xanthomonas axonopodis pv.citri?Xac?.The EC₅₀0 value of compound B₁on Xoo and Xac were 26.2 and 10.1?g/mL,respectively.These were much better than that of the thiodiazole copper(The EC₅₀0 values of thiodiazole copper were 97.2 and35.3?g/mL,respectivly).Compound B₁₇7 possesses EC₅₀0 value of 7.2?g/mL on Xoo and was superior to commercial bismerthiazol?57.2?g/mL?.Based on the results of biological active results,the preliminary SAR was analyzed.Some of the active compounds can be further optimized as a lead compound for innovation of novle bacterial drug for plants.The research of this thesis lays a certain foundation for the inovation of new anti bacterial oxadiazole derevtives.