Design, Synthesis And Biological Activity Of 1,2,4- Triazolo [1,5-a] Pyrimidine Compounds

In recent years, the social and environmental requirement for agricultural safety has been greatly enhanced.Developing new pesticides that possess the feature of low toxicity, high-performance and environmental-friendliness is extremely urgent. For example, there are many varieties of herbicides, but targets are few.People has to use the same or similar target herbicides, leading to increased resistance of crops. Therefore the development of new herbicide targets is especially important. Recent studies revealed that the enzymes in the non-mevalanate pathway, also known as the MEP pathwy for the synthesis of isoprene compounds, may be ideal targets for herbidise development due to the fact that the pathway presents only in plants and bacteria, including a variety of pathogens, not in animals. IspD enzyme catalyzes the third stage in MEP pathway.It can be used as the potential herbicide target. Triazolopyrimidine compounds have a wide range of appli-cations as medicines and pesticides.For examples, exhibiting a broad specreum of hebicidal activity. We virtually screened a number of compounds by using molecular docking.Then two kinds of triazolopyrimidine derivatives,6-substituted-7-amino-5-chlorine-1,2,4-trizolo[1,5-a]pyrimidine and 1,2,4-triazolo[1,5-a]pyrimidine carboxylates or acids were designed and synthesized through using the methodology of the active substructure combination.The compounds were characterized by 1H NMR,13C NMR, MS and FTIR.The herbicidal activity was also tested.The details are as follows:1.The structure and function of the protein IspD as well as the development of inhibitors based on this target protein were overviewed.The applications of 1,2,4-triazolo[1,5-a]pyrimidine compounds in herbicides and fungicides as well as other fields were summarized.The general methods of the synthesis of this class of compounds were also described.2. Design and synthesis of target compounds:we screened virtually a group of triazolopyrimidine compounds by the way of computer techonology. We designed two kinds of target compounds through using the methodology of the active substructure combination.The ring closure between 3-amino-1,2,4-triazole and dicarbonyl compounds were used to generate the intermediates 5-hydroxy-1,2,4-triaolo[1,5-a]pyrimidine,which were then reacted with POCl3 to produce chlorinated intermediates.Finally the interme-diates reacted with amines yield terget compounds.In addition.the 5-hydroxy-substituted intermediates were reacted with a-halocarboxylate to generate 1,2,4-triazolo[1,5-a]pyrimidine.Those target compounds have not been reported in the literature. All the compounds were characterized by 1H NMR,13C NMR, MS and FTIR.3. By using the method of Petri dish test, the herbicidal actibvity of the synthesized compounds was assayed.Results showed that most compounds have a certain amount of activity against the growth of root and stem of rape and Lolium.And the inhibitory activity of root is higher than the inhibitory activity of stem.