2,5-双取代-1,3,4-噁二唑类化合物的合成与表征

以3-( 4-氟苯基) -1H-吡唑-5-甲酸乙酯为原料，与H2NNH2?H2O发生肼解生成3-( 4-氟苯基) -1H-吡唑-5-甲酰肼，再与CS2环化生成2-巯基噁二唑中间体，最后在巯基上进行烷基化反应合成了一系列新型的2-硫醚-5-吡唑基-1,3,4-噁二唑类化合物，并利用IR、1H NMR、HRMS等波谱技术对目标化合物结构进行了表征。该合成方法具有原料易得，后处理简便，收率较高的优点。

Synthesis and characterization of 2,5-disubstituted-1,3,4-oxadiazole derivatives

Eight novel 2-alkylthio-3-5-(4-fluorophenyl)-1H-pyrazole-5-yl]-1,3,4-oxadiazole derivatives (4a-h) were readily prepared by the reaction of ethyl 3-(4-fluorophenyl-1H-pyrazole-5-carboxylate as the starting material with hydrazine hydrate to give 3-(4-fluorophenyl)-1H-pyrazole-5-carbohydrazide (2) which on reaction with carbon disulfide in the presence of potassium hydroxide, followed by subsequent thioetherification with the various halohydrocarbons. All the compounds have been characterized by the melting point, IR, 1H NMR and HRMS. This synthetic method has the advantages of available starting materials, simple operations and high yields.