The α-bromination reaction of carbonyl compounds is a significant topic in the field of organic chemistry. However, due to the lack of suitable brominating reagents, the application of this reaction in undergraduate organic chemistry experiments is limited. In this study, three junior undergraduates successfully conducted an innovative experiment under the guidance of teachers. The bromination of various acetophenone derivatives was investigated by employing pyridine hydrobromide perbromide as the brominating agent, with a focus on exploring the effects of reaction time, reaction temperature, and dosage of the brominating agent. The results demonstrated that 4-chloro-α-bromo-acetophenone could be synthesized at 90 ℃ using 4-chloroacetophenone as a substrate and acetic acid as a solvent with a molar ratio of substrate to brominator being 1.0:1.1. Through the experimental teaching of 18 junior undergraduates, it was observed that all the students successfully completed the experiment within a time frame of 4–5 h, with a notable achievement yield exceeding 80% observed in 14 students. This innovative experiment exhibits significant advantages in terms of safety, high yield, cost-effectiveness, and repeatability. Furthermore, while reinforcing fundamental skills in chemistry experimentation among students, it enhances their scientific literacy levels and fosters innovation consciousness as well as practical aptitude. Consequently, this approach is highly suitable for widespread implementation and integration into undergraduate experimental pedagogy.

中文翻译：

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苯乙酮衍生物的α-溴化反应在实验教学中的应用——一个低年级本科生的化学创新实验

羰基化合物的α-溴化反应是有机化学领域的一个重要课题。但由于缺乏合适的溴化试剂，该反应在本科生有机化学实验中的应用受到限制。本研究中，三名大三本科生在老师的指导下成功进行了创新实验。以氢溴酸吡啶为溴化剂，研究了各种苯乙酮衍生物的溴化反应，重点探讨了反应时间、反应温度和溴化剂用量的影响。结果表明，以4-氯苯乙酮为底物，乙酸为溶剂，底物与溴化剂的摩尔比为1.0:1.1，在90 ℃下可以合成4-氯-α-溴苯乙酮。通过对18名大三本科生的实验教学，所有学生均在4~5小时内顺利完成实验，其中14名学生成绩合格率超过80%，成绩显着。这一创新实验在安全性、高产率、成本效益和可重复性方面表现出显着的优势。此外，在强化学生化学实验基础技能的同时，提高学生的科学素养水平，培养创新意识和实践能力。因此，这种方法非常适合广泛实施并融入本科生实验教学法。