Method for continuously preparing 3, 5-dinitrobenzoic acid by using micro-channel reactor

The invention discloses a method for continuously preparing 3, 5-dinitrobenzoic acid by using a micro-channel reactor, and belongs to the technical field of organic synthesis processes. According to the method, benzoic acid and concentrated nitric acid are used as raw materials, fuming sulfuric acid is used as a solvent, trifluorosulfonic acid ketone is used as a catalyst, and the preparation process of 3, 5-dinitrobenzoic acid is continuously completed in a micro-channel reactor system. After the raw materials are introduced into the micro-channel reactor through a metering pump, the 3, 5-dinitrobenzoic acid product is obtained through preheating, mixed reaction and separation, the method can strictly control the temperature and the retention time in the reaction process, accurately control the reaction temperature to prevent temperature runaway, and improve the safety of a reaction device; and due to the strong mass transfer effect of the micro-channel reactor, the mass transfer effect among the raw materia