苯甲酸、对氨基苯甲酸乙酯、乙酰苯胺三组分分离实验教学设计

Design of a Separation Experiment for Three Components of Benzoic Acid,Ethyl P-Aminobenzoate and Acetanilide

为锻炼学生综合运用萃取、蒸馏、重结晶等纯化实验操作,提高学生从混合物中分离并提纯目标化合物的实验技能,中南大学化学化工学院有机化学教学组在有机化学实验教学中安排了“三组分混合物的分离”实验,面向临床医学(五年制、八年制)、药学、生物科学等专业,以及化学化工学院所有专业。鉴于对甲苯胺有毒性,给做实验的学生、实验室教师和指导教师身体带来较大危害,产生的废水对环境也有相当的危害。同时,由于其熔点低,实验室教师每次都要准备冰块,不利于节能省电。尝试使用绿色无毒、熔点较高的对氨基苯甲酸乙酯替代对甲苯胺,可以很好地避免上述两个问题,我们在实验室反复多次做了先加酸或先加碱的两种分离方案后,在有机化学实验B的教学中进行了初步推广,取得了良好的教学效果。

The“Separation of three organic component mixtures”experiment is arranged by the organic chemistry teaching group of the College of Chemistry and Chemical Engineering of Central South University.The aim is to develop college students’skills of separation and purification by testing their understanding of and ability to use the principles of extraction,distillation and recrystallization.This experiment is designed for fifth and eighth-year students pursuing studies in clinical medicine,pharmaceutical sciences,biological sciences and applied chemistry.One experimental component,p-toluidine,poses a risk to students,teachers,and laboratory staff due to its toxicity,and wastewater generated does considerable harm to the environment.Furthermore,p-toluidine requires the preparation of ice to facilitate its low melting point,which is not conducive to energy-saving goals.Hence,this paper presents a modified experiment where p-toluidine is replaced by ethyl p-aminobenzoate,a greener,non-toxic alternative which has a higher melting point.After conducting two test acid/alkali separations in the laboratory,Organic Chemistry Experiment B was launched and received positive feedback.