Containing 1,3,4 - Thiadiazole Derivatives, Synthesis And Biological Activity Study Of Yl (sulfoxide)

Sulfoxide and sulfone compounds possess broad spectrum of bioactivities,such as insecticidal,antifungal,herbicidal,antitumor,anti-HIV-1 and antitubercular activities et al.In recent years,sulfoxide and suifone compounds were used widely as agrochemicals.For example, Aventis developed insecticide named as Fipronil which possessed broad spectrum of bioactivity against Myzus persieae,Empoasca,larvae of Lepidoptera,Musca domestica and Hymenoptera pests.SDC biotechnology developed sulfone herbicide Benzobicyclon,which was a kind of HPPD(4-hydroxyphenyl pyruvate dioxygenase) inhibitior.Aventis exploited sulfone containing herbicide Isoxaflutole,which was mainly used in weeds of maize and sugar beet fields. Therefore,sulfoxide and sulfone compounds have been one of the focuses in chemical and biological research fields.In order to find high-effcient and environment friendly pesticidal compounds,this paper hoped to start from gallic acid and synthesized a series of sulfoxide derivatives,we designed and synthesized nine new 2-substituted thio-5-(3,4,5-trimethoxyphenyl)-1,3,4-thiadiazole (oxadiazole) compounds(series A),two new 2-substituted sulfonyl-5-(3,4,5-trimethoxyphenyl) -1,3,4-thiadiazole compounds(series B) and nine new 2-substituted sulfinyl-5-(3,4, 5-trimethoxyphenyl)-1,3,4-thiadiazole compounds(series C).Structures of all new compounds were identified by ¹H NMR,¹³C NMR,IR and elemental analysis.The preliminary bioassay tests showed that 2-substituted sulfinyl-5-(3,4,5-trimethoxy -phenyl)-1,3,4-thiadiazole compounds(series C) displayed certain antifungal activity.