关键词: 绿色化学, 卤素交换, 1,3-二氯丙酮, 1,3-二溴丙酮, 溴化锂

Abstract: Based on the general process of synthetic chemistry methodology and the “scientific problem-oriented” principle in laboratory teaching, this paper has developed a basic experiment of organic chemistry derived from the green synthesis of 1,3-dibromoacetone, and firstly applied halogen exchange reaction to laboratory teaching. Starting with 1,3-dichloroacetone and lithium bromide, the halogen exchange equilibrium was broken efficiently using mixture solvent of dichloromethane and acetone (10 : 1). Therefore, in the presence of 3.5 equivalents of lithium bromide, the green synthesis of 1,3-dibromoacetone was achieved with 97% isolated yield after refluxing 1.5 hours at 40 °C. The purity of desired product was higher than 97%, and up to 98.8% after recrystallization. The all reagents used in this experiment are safe and environmentally benign. The teaching time is about 4 hours, which not only involves basic operations of various organic chemistry experiments, but also includes important aspects such as reaction monitoring, structure characterization, and purity analysis. It is very suitable for basic organic chemistry laboratory teaching. At the same time, based on this experimental scheme, combined with the micro-course learning and exercises on the development history of halogen exchange reaction in application and development of 1,3-dibromoacetone, the interaction between theoretical knowledge and synthetic practice was realized. This improved the comprehensive ability of undergraduate of chemistry majors to solve synthetic chemistry problems and solidified the quality of talent cultivation in the field of chemistry.

Key words: Green chemistry, Halogen exchange, 1,3-Dichloroacetone, 1,3-Dibromoacetone, Lithium Bromide