香豆素-3-羧酸制备实验的改进与拓展设计

Improvement and Extensive Design of the Synthesis of Coumarin-3-carboxylic Acid

香豆素-3-羧酸的制备是一个经典实验,一般是以水杨醛和丙二酸二乙酯为原料,在哌啶催化下加热回流2 h,经过两步完成。我们对该实验进行了以下改进与拓展:1)以水杨醛和米氏酸为原料,水为溶剂,在90℃下加热搅拌30 min,即可得到香豆素-3-羧酸;同时改变底物实现7-(二乙氨基)香豆素-3-羧酸的制备;2)通过观察香豆素-3-羧酸和7-(二乙氨基)香豆素-3-羧酸与稀土离子Eu^(3+)混合溶液的荧光,引入计算化学验证香豆素-3-羧酸和7-(二乙氨基)香豆素-3-羧酸对Eu^(3+)的能量转移性质。本实验涉及多个学科的重要知识点,具有较强的模块性、综合性、趣味性、教学可行性,有利于培养学生的创新能力与综合应用能力。

The preparation of coumarin-3-carboxylic acid is a classical chemistry experiment.In this experiment,the reactants,salicylaldehyde and diethyl malonate,as well as the piperidine catalyst are mixed under reflux for 2 h to obtain coumarin-3-carboxylic acid after base hydrolysis and acidification.We have made the following improvements and extensive designs to the experiment:1) By substituting diethyl malonate with Meldrum’s acid,coumarin-3-carboxylic acid can be obtained by heating at 90℃ for 30 min in water,and 7-(diethylamino)coumarin-3-carboxylic acid can be synthesized by changing the substrate;2) Observing the fluorescence of the solution with Eu^(3+),coumarin-3-carboxylic acid,and 7-(diethylamino)coumarin-3-carboxylic acid and using computational chemistry can help verify the energy transfer property.The modified experiment,which involves a number of important multidisciplinary knowledge points,has strong modularity,comprehensiveness,interest,and teaching feasibility.Moreover,it is conducive to cultivating students’innovative and comprehensive application abilities.