The Synthesis Of Isoxazole And Pyrazole Heterocyclic Derivatives

In recent years, organic heterocyclic compounds have been developed rapidly in the field of organic chemistry, and take an important signification not only in theory but also in practical application aspects. In the research and exploitation of medicine and pesticide, heterocyclic compounds containing nitrogen play a key role and is a focus of the research of druggery nowadays. The heterocyclic compounds containing nitrogen such as isoxazole, pyrazole, thiadiazine are some important compounds of biological activity and play an extensive application in modern medicine and pesticide aspects. There are mostly biological activities, such as antibacterial, antiphlogistic, acesodyne, anticonvulsant, anticancer, bactericide, herbicide, pesticide and plant growth regulator and so on, so many druggery chemists and pesticide learners pay attention to these heterocyclic compounds. In view of these observation and expect to realize the enforcement of many physiological activities, we combined with different heterocycles of isoxazole, pyrazole, thiadiazine into the same molecule and synthesized a series of isoxazole and pyrazole derivatives with novel structures.The thesis includes two major parts:The first part is about literature review. The important biological activity, synthetic methods and chemical characteristics of the isoxazole, pyrazole and thiadiazine derivatives that have been studied in china and other countries were explicated systematically and briefly.The second part is about experimental content. Major work as follows:1 Synthesis of a series of 3-alkyl(or aryl)-6-(3-aryl-5-methyl-isoxazol-4-yl)-7H-1,2,4- triazolo[3,4-b]-1,3,4-thiadiazine derivatives with 3-aryl-4-(α-bromoacetyl)-5-methyl-isox- azol and 3-alkyl(or aryl)-4-amino-5-mercapto-1,2,4- thiadiazine.2 Synthesis of biisoxazole compounds: 3-aryl-5-aryl-4-[(3-aryl-5-methyl-isoxazol-4-yl)– carbonyl] isoxazole by the reation of 1,3-dipolar cycloaddition withα,β-unsaturated ketone of isoxazole compounds and nitrile oxides3 Synthesis of 3-aryl-5-(1-phenyl-3-methyl-5-phenoxyl-pyrazol-4-yl)-4-aroyl-4,5 dihydro- isoxazole by the reation of 1,3-dipolar cycloaddition withα,β-unsaturated ketone of pyrazole compounds and nitrile oxides, isoxazole molecule was added into the pyrazole compounds. 4 Synthesis of a series of 1-H(or phenyl)-3-aryl-5-(1-phenyl-3-methyl-5-phenoxyl-pyrazol-4- yl)-4,5-dihydropyrazoline derivatives have been efficiently synthesized under refluxing in glacial acetic acid withα,β-unsaturated ketone of pyrazole compounds and two kinds of hydrazines.Above all, the structures of new compounds were confirmed on the basis of 1H NMR, IR spectrum and element analysis, and single crystal X-ray diffraction.