Synthetic method for 1,2,4-trifluorobenzene

The invention provides a synthetic method for 1,2,4-trifluorobenzene, belongs to the field of pesticide, medicine, and liquid crystal material intermediate preparation, and solves the problem of harshreaction conditions of a current method for synthesizing 1,2,4-trifluorobenzene. The synthetic method for the 1,2,4-trifluorobenzene is characterized by comprising the following steps: performing nitration by using 2,4-dichlorofluorobenzene as a raw material and nitric acid as a nitrating agent to form 2,4-dichloro-5-fluoronitrobenzene in the presence of sulfuric acid; dissolving the 2,4-dichloro-5-fluoronitrobenzene into an organic solvent, adding potassium fluoride and a first catalyst, and performing fluorination under the catalysis of the first catalyst to obtain 2,4,5-trifluoronitrobenzene; dissolving the 2,4,5-trifluoronitrobenzene into a solvent, and performing hydrogenation reduction with hydrogen under the catalysis of a second catalyst to obtain 2,4,5-trifluoroaniline; and performing a reaction on the 2