乙酰乙酸乙酯合成实验中产品验证方法的改进

An Improved Method for the Assay of Product Purity in the Experiment of the Synthesis of Ethyl Acetoacetate

在总结实验教学实践的基础上,对乙酰乙酸乙酯合成实验中产品的验证方法加以改进,采用核磁共振技术来验证乙酰乙酸乙酯产品的质量,克服了减压蒸馏方法沸点数据没有可比性、传统化学方法检验乙酰乙酸乙酯烯醇式结构无法定量的缺点。利用核磁共振技术定量验证了乙酰乙酸乙酯烯醇式结构的存在,让学生直接观察到溶剂对乙酰乙酸乙酯烯醇式含量的影响。提出简易核磁共振测试方法(无氘代溶剂消耗),减少氘代溶剂的使用,既降低了实验成本,又显著提高了实验教学效果。

Based on the practical pedagogical experience of many experimental classes, it presents a new improved method adopting the nuclear magnetic resonance （NMR） technique to assay the quality of ethyl acetoacetate in its synthesis. Traditional methods commonly adopted in class teaching each have their drawbacks. The method involving the measurement of boiling point suffers at an unimanous reduced pres- sure for different vaccum systems,while other chemical methods are unable to quantify the content of the enol form in the ethyl acetoacetate product. The NMR method was proposed in this paper which could quantify the content of the enol form of ethyl acetoacetate, enabling students to have a direct observance of the solvent influence on the content of the enol form. Moreover, the new simplified NMR methods could not consume deuterated solvents,which could reduce the cost of the experiment and enhances the peda- gogical effects of the class.