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苯并咪唑类化合物在医药、照相及染料工业中都有广泛的应用.本文报道苯并咪唑冠醚及其季铵盐(1—5)的合成. 苯并-15-冠-5于0℃用发烟硝酸一步二硝基化得6,与冰醋酸-70％HNO_3硝化体系相比,这一方法反应时间短,产物纯化简便,收率较高.在冰醋酸-醋酐介质中,6分别用锌粉或SnCl_2-HCl进行还原缩合.结果表明,后者较佳,用锌粉还原时只分离到4,5-二乙酰氨基苯并-15-冠-5(7).
Benzimidazoles have been widely used in the pharmaceutical, photographic and dye industries.In this paper, the synthesis of benzimidazole crown ethers and their quaternary ammonium salts (1-5) Compared with acetic acid -70% HNO3 nitration system, the reaction time is short and the product is purified easily and has high yield with fuming nitric acid in one-step dinitration.6 In the acetic acid-acetic anhydride medium, 6 Respectively, with zinc powder or SnCl 2 -HCl for reduction and condensation.The results show that the latter is better, with zinc powder only isolated 4,5-diacetamido-15-crown-5 (7).