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3— ( 2′—羧乙基 )苯并噻吩作为一种极为重要的化工原料 ,其传统的合成方法 ,产率仅达 60 %左右 ,实验条件难以掌握。为提高该物质的收率 ,降低原料消耗 ,寻求较为理想的合成方法 ,文中介绍了以苯并噻吩、丙二酸二乙酯、氢化钠为主要原料 ,合成 3— ( 2′—羧乙基 )苯并噻吩的方法。经大量合成实验条件探索 ,苯并噻吩的氯甲基化在室温下进行 ,用氢化钠代替醇钠 ,用二甲基甲酰胺 (DMF)为溶剂 ,在加热条件下进行均相脱羧反应 ,抑制了副反应的发生 ,从而提高了产品收率。并经熔点测定 ,1 H -NMR、1 3C -NMR、质谱及元素分析 ,表征其合成得到的 3— ( 2′—羧乙基 )苯并噻吩的结构。
3- (2’-carboxyethyl) benzothiophene as an extremely important chemical raw material, its traditional synthesis method, the yield of only about 60%, the experimental conditions are difficult to grasp. In order to improve the yield of this material and reduce the consumption of raw materials, we find the ideal synthesis method. In this paper, benzothiophene, diethyl malonate and sodium hydride are used as main raw materials to synthesize 3- (2’-carboxyethyl ) Benzothiophene. After a large number of synthetic experimental conditions to explore, chlorothymethylation of benzothiophene at room temperature, with sodium hydride instead of sodium alcoholate, dimethylformamide (DMF) as a solvent, under homogeneous conditions decarboxylation reaction, inhibition The occurrence of side effects, thereby increasing product yield. The structure of 3- (2’-carboxyethyl) benzothiophene synthesized by the method was characterized by melting point determination, 1 H-NMR, 1 3C-NMR, mass spectrometry and elemental analysis.