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