阿司匹林合成实验中反应条件的影响研究

Effects of Reaction Conditions on the Experimental Synthesis of Aspirin

本文针对化工专业课《有机化学品合成与工艺》学生普遍反映的知识点繁多,对某一具体化学品的合成路线、工艺条件、操作特点难以选取和掌握的情况,以化学品阿司匹林为例,在实验室合成中进行演示教学。对不同催化体系下水杨酸与醋酸酐反应制备阿司匹林的反应条件进行系统考察,优化出最佳反应条件,从而达到抑制副反应提高主产物收率的目的。分别以浓硫酸、乙酸钠、吡啶为催化剂,考察温度和时间对各自反应的影响,采用紫外分光广度法分析产物纯度,并以此计算产物收率。实验发现乙酸钠催化水杨酸与醋酸酐反应制得的阿司匹林收率最高,最佳条件为在55℃下反应50分钟,可得到83.9%的阿司匹林。通过本实验演示,可以使学生们亲身体会到在有机化学品合成过程中如何解决工艺问题。

This paper is aimed to systematically investigate the reaction conditions under different catalytic systems for the synthesis of aspirin by the reaction of salicylic acid and acetic anhydride.The side reaction is restrained by optimize the reaction conditions.Thus the yield of aspirin is improved.With concentrated sulfuric acid,sodium acetate and pyridine as catalysts respectively,the influences of temperature and time on the reaction are studied.The purity of the product is analyzed using ultraviolet spectroscopy to calculate the yield.The experiment results suggest that the highest yield of aspirin is obtained by the sodium acetate catalyzed reaction of salicylic acid and acetic anhydride.The optimum reaction at 55℃for 50 minutes can give 83.9%yield of aspirin.