微波辅助蜜胺甲醛树脂负载硫酸催化合成5-取代四氮唑

Microwave-assisted Synthesis of 5-Substituted 1H-Tetrazoles Catalyzed by Melamine Formaldehyde Resin Supported Sulfuric Acid

以蜜胺甲醛树脂负载硫酸为固体酸催化剂,在微辐射下,利用苄基腈或芳基腈和叠氮化钠在N,N-二甲基甲酰胺(DMF)溶剂中的环加成反应,一步法制备得到5-取代四氮唑类化合物3a^3j,其结构经IR、1 H NMR和元素分析等表证;实验结果表明,在催化剂摩尔分数为20%,400 W,120℃,微波辐射下反应25~30min,目标化合物3a^3j收率为80%~92%,该方法具有操作简单、催化剂易回收和能多次使用等优点。

A melamine-formaldehyde resin supported sulfuric acid catalyzed the cycloaddition of benzyl or aryl nitriles and sodium azide in N,N-dimethylformamide(DMF)under microwave irradiation to form 5-substituted 1 H-tetrazoles(3 a^3 j)is described.The structures of the corresponding products were confirmed by IR,1H NMR spectra and elemental analysis.The results indicated that the melamineformaldehyde is available to loading of sulfuric acid and with the amount of 20%under microwave irradiation at 400 Wand 120℃to 25~30 min,the target compounds 3 a^3 j were obtained in 80%~92%yields.This method has some distinct advantages such as ease of product purification and the reusability of the catalyst.