2,4,5-Trifluorobenzoic acid is a valuable synthetic intermediate with important application in pharmaceutical industry and material science. In this paper, we report a facile continuous microflow process for the synthesis of 2,4,5-trifluorobenzoic acid via the generation of an unstable aryl-Grignard reagent followed by its reaction with gaseous CO₂. The microflow system is easily assembled by a simple T-micromixer, a commercial available falling film microreactor, tube microreactor and several pumps. The use of a composed T-micromixer and tube microreactor facilitates the Grignard exchange reaction of 2,4,5-trifluorobromobenzene with ethylmagnesium bromide producing 2,4,5-trifluorophenylmagnesium bromide almost in quantitative yield, and the use of the falling film microreactor enables a highly efficient gas–liquid reaction of the resultant Grignard reagent with CO₂ under an atmosphere pressure, which ultimately gave the product 2,4,5-trifluorobenzoic acid in high yield with high purity after a simple and extractive workup. The influence of reaction parameters on the two steps in microreactors was discussed.

2,4,5-三氟苯甲酸是一种有价值的合成中间体，在制药工业和材料科学中具有重要的应用。在本文中，我们报告了一种通过生成不稳定的芳基格氏试剂然后与气态CO ₂反应来合成2,4,5-三氟苯甲酸的简便连续微流工艺。通过简单的T型微混合器，可商购的降膜微反应器，管式微反应器和数个泵，可以轻松组装微流系统。使用组成的T-微混合器和管式微反应器可以促进2,4,5-三氟溴苯与乙基溴化镁的格利雅交换反应，从而几乎可以定量地获得生成2,4,5-三氟苯基溴化镁，并且使用降膜微反应器可以实现在大气压下，最终的格氏试剂与CO ₂进行了高效的气液反应，经过简单的萃取后，最终以高收率和高纯度得到了2,4,5-三氟苯甲酸产物。讨论了反应参数对微反应器两步反应的影响。