大学化学 >> 2024, Vol. 39 >> Issue (5): 238-242.doi: 10.3866/PKU.DXHX202311066

所属专题: 第4届全国大学生化学实验创新设计大赛

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光引发格氏试剂合成与三苯甲醇制备实验改进

成万民, 都娟, 刘佩雯, 蒋逸云, 江洪   

  1. 华中农业大学化学学院, 武汉 430070
  • 收稿日期:2023-11-20 修回日期:2024-02-04 发布日期:2024-04-03
  • 通讯作者: 江洪 E-mail:jianghong@mail.hzau.edu.cn
  • 基金资助:
    国家自然科学基金(22301091)

Photoinitiated Grignard Reagent Synthesis and Experimental Improvement in Triphenylmethanol Preparation

Wanmin Cheng, Juan Du, Peiwen Liu, Yiyun Jiang, Hong Jiang   

  1. College of Chemistry, Huazhong Agricultural University, Wuhan 430070, China
  • Received:2023-11-20 Revised:2024-02-04 Published:2024-04-03
  • Contact: Hong Jiang E-mail:jianghong@mail.hzau.edu.cn

摘要: 在大学有机化学实验中,通过格氏试剂与苯甲酸酯反应制备三苯甲醇是一项经典的实验教学项目。该实验通常利用碘加热方法引发制备苯基溴化镁,但碘加热引发过程不易控制,且易产生副产物联苯,导致产率不高,甚至部分学生不能成功得到格氏试剂,导致实验失败。本文通过光照的方法来引发制备格氏试剂,无需碘加热引发。在520 nm的LED灯光照下,溴苯和镁可以直接反应得到苯基溴化镁,反应不需要加热,即使在−10 °C下都可以顺利进行。该光源廉价易得,改进后的光照方法能够使格氏试剂合成时间缩短、产率提高,实验成功率也得以提升,因此该方法值得在全国其他高校推广应用。

关键词: 三苯甲醇, 格氏试剂, 光化学, 改进

Abstract: In university organic chemistry experiments, the classic teaching project of synthesizing triphenylmethanol by reacting Grignard reagent with benzoate often encounters challenges with the conventional method of initiating the reaction using iodine heating. This approach is difficult to control and prone to generating by-products like biphenyl, leading to low yields. Furthermore, some students may fail to obtain the Grignard reagent, resulting in experiment failure. In this study, we propose a photoinitiated method for synthesizing the Grignard reagent, eliminating the need for iodine heating. Under 520 nm LED irradiation, bromobenzene reacts directly with magnesium to form phenylmagnesium bromide without requiring external heating, even at temperatures as low as?10°C. This cost-effective and readily available light source significantly shortens synthesis time, improves yield, and enhances experimental success rates. Therefore, this innovative approach holds promise for wider adoption and application in university settings.

Key words: Triphenylmethanol, Grignard reagent, Photochemistry, Improvement