Study On The Synthesis Of 1-Chloro-2, 6-difluorobenzene

1-Chloro-2,6-difluorobenzene is a kind of important organic chemical raw material and intermediate, which can be widely used as medicines, pesticides, and veterinary products, and other chemical industries. A convenient preparation of high-purity 1-chloro-2,6-difluorobenzene has been developed. The key to the isolation of the desired isomer, without contamination of the difficult-to-separate isomer 1-chloro-2,3-difluorobenzene.The synthesis of l-chloro-2,6-difluorobenzene was investigated and improved in this paper. Although the process requires four reaction steps, it does offer some advantages. It uses cheap rap raw materials, such as chlorine sulfonic acid, potassium fluoride, and trichlorobenzene. The yield of sulfonation and last product are over 80% and 29.8% respectively. The purity of last product is over 95%. Many factors which affect the fluorination reaction and hydrolysis reaction, such as ratio of batching, reaction temperature, volume of sulfuric and reaction time have been studied. The better fluorination reaction conditions are as follows: the ratio of trichlorobenzene to chlorine sulfonic acid is 1:5.1, reaction temperature is 85℃, the reaction time is 3h. The better hydrolysis reaction conditions are as follows: the volume of sulfuric is 125 mL, the concentration of sulfuric is 50%, the reaction time is 4h. The process for the production of low-cost, small industrial pollution, will have broad market prospects.