Study On Synthesis And Biological Activity Of Novel Nitrogen-Containing Heterocyclic Derivatives

In this paper, the current approaches to pesticide discovery were reviewed. Based on the known highly effective molecular to screen new compounds, it is an important way to develop new pesticides. A principal means of this way is Substructure Link Way. In order to shorten the creation process and reduce the cost of new pesticides development, it is necessary to invent new ways. Since the cluster effect has been widely applied in drug design, we believe that this method can serve as reference and guidance for the discovery of new agrochemicals.The novel heterocyclic compounds, especially, the nitrogen-containing, have become the mainstream of agrochemical research, because their structures are similar to the alkaloids'body, such as purine and pyrimidine. Therefore they have high specificity to the target, and excellent environmental compatibility. Dozens of heterocyclic compounds have been used as insecticide, herbicide, and fungicide. Among them, thiadiazole and pyrazole derivatives are two kinds of important nitrogen-containing heterocyclic compounds.This paper mainly contains two parts as bellow.Partâ… : Baesd on the cluster effect principle, eighteen novel bivalent compounds were designed and synthesized using 2-amino-5-sulfhydryl-1, 3, 4-thiadiazole as precursor. The structures of the target compounds were confirmed by 1H NMR and elemental analysis. The bactericidal activity of all target compounds was evaluated, and part of the bivalent thiadiazoles compounds showed bactericidal activity in the preliminary test.Partâ…¡: Study on structure-activity relationship of benzoylphenylureas revealed that 2, 6-difluoro moiety in the benzoylurea is critical to its activity. Baesd on the Substructure Link Way, we designed and synthesized a series of new N-(2, 6-difluorobenzoyl) urea compounds by substituting pyrazole for the terminal NH2. The structures of the target compounds were confirmed by 1H NMR, IR and elemental analysis. In the preliminary biological test, these compounds showed insecticidal activity against Spodoptera exigua, Plutella xylostella(L.) and Helicoverpa armigera. Among them, compounds 4b, 4k, 4l exhibit herbicidal activities.