Potassium fluoride,anhydrous
           Potassium fluoride,extra pure
           Potassium fluoride,Granular
           Silicon Dioxide
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           Potassium Fluoaluminate
           Ammonium bifluoride
           Potassium Bifluoride
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           Sodium fluoride
           Potassium Fluorosilicate
           Fluorosilicic Acid
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           Magnesium fluorosilicate
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The non - polar solvent DMF was used as the reaction medium, and the corresponding fluorinated products were synthesized by halogen - exchange fluorination using tetrachloride (p -) phthalonitrile and active potassium fluoride as raw materials. In the process of fluorination, trace moisture in the reaction system is the main factor affecting the reaction, therefore, the raw materials, potassium fluoride and the reaction solvent drying water is particularly important.

5-Chloro-2,4,6-Trifluoroisophthalonitrile and Tetrafluoroterephthalonitrile are important fluorine-containing aromatic chemical intermediates, widely used in pharmaceuticals, pesticides, dyes and fluoropolymers synthesis. With their synthetic pesticide selectivity, the use of small, low toxicity, low residue, the development prospects are very broad, with high value, good market prospects. Fluorination of tetrachlorobenzonitrile can be achieved through a variety of ways, mainly fluoride replacement method, diazotization method, halogen exchange fluorination method. Halogen exchange fluorination reaction is one of the effective methods for the synthesis of fluorine-containing organic compounds, and it is also widely used in the industry. The method is the use of alkali metal fluoride (such as KF) and aromatic ring containing other halogen (that is, chlorine, bromine, iodine) of the aromatic compounds, with fluorine atoms to replace other halogen atoms.

In this paper, a simple method is used to treat potassium fluoride and solvent without water, and potassium hydroxide and solvent are distilled under vacuum to distill off some of the solvent so that ω (H_2O) is less than 0.05% Fischer method to accurately determine the moisture content of the fluorination system before and after removal of water to meet the reaction system required for fluorination in order to obtain a better reaction effect. The effects of reaction temperature, reaction time, ratio of reaction materials and solvent type and solvent dosage on the yield of the product were investigated. The fluorinated products were synthesized under the existing experimental conditions. (1) The optimum conditions for the synthesis of 5-chloro-2,4,6-trifluoroisophthalonitrile by halogen exchange were determined as follows: n (chlorothalonil): n (KF) = 1: 4, reaction temperature: 85 ~ 88 ℃, reaction time: 2.5h, tetrachloroisophthalonitrile and solvent DMF dosage of the mass ratio of 1: 4.7. Under these conditions, the yield can reach more than 82.52%. (KF) = 1: 8.5, reaction temperature: 110 ~ 115 ℃, reaction time (KF) = 1: 5, the reaction temperature was 110 ~ 115 ℃, and the reaction time was as follows: (2) The optimum conditions for the synthesis of tetrafluoroterephthalonitrile were determined by halogen exchange. Reaction time: 4.0h, the mass ratio of tetrachloroterephthalonitrile to solvent DMF was 1: 12.5. Under these conditions, the yield can reach more than 83.53%, relative to the reported product yield and purity are all improved. The process has the advantages of low raw material cost, mild reaction condition, simple operation condition and good product yield. It has guiding significance for industrial production.