A process for the preparation of fluoroethane sulfonyl fluoride

Abstract

The application discloses a preparation method of fluoroethane sulfonyl fluoride, and is characterized by comprising the following steps: 1, dissolving chloroethane sulfonyl chloride in an organic solvent, adding a phase transfer catalyst, an iodine salt catalyst and an acidic fluorination reagent, and then performing fluorination reaction after heating; the organic solvent is selected from one of ethyl ether, methyl tert-butyl ether, tetrahydrofuran, ethyl acetate, dimethyl carbonate and acetonitrile; the iodine salt catalyst is selected from one of potassium iodide and sodium iodide; and the acidic fluorination reagent is selected from one of triethylamine trihydrofluoride, ammonium bifluoride and potassium bifluoride; 2, after the reaction is completed, the reaction liquid is washed with water, the solvent is evaporated, and then the concentrated liquid is rectified to obtain the fluoroethane sulfonyl fluoride product. The application has the advantages of simple process steps, mild and controllable reaction, high product yield and high purity.

Description

Technical Field

[0001] This invention relates to the field of compound synthesis technology, specifically to the synthesis of fluoroethanesulfonyl fluoride. Background Technology

[0002] Fluorine is highly electronegative, and fluorinated organic compounds possess low freezing points, high flash points, and high oxidation resistance, which are beneficial for improving the contact performance between lithium battery electrolytes and electrodes. Fluorinated solvents or additives can improve the low-temperature performance, oxidation resistance, flame retardancy, and wettability of the electrolyte to the electrodes, thereby contributing to improved battery thermal stability and safety. Sulfonyl fluorides, as a novel type of electrolyte functional additive, can enhance the oxidation resistance of the electrolyte in high-voltage systems and inhibit side reactions at the electrolyte-cathode interface, effectively improving the cycle stability of the battery under high voltage and high temperature conditions.

[0003] Currently, the known method for synthesizing fluoroethanesulfonyl fluoride involves using potassium hydrofluoride as the fluorinating agent. Fluoroethanesulfonyl chloride and potassium hydrofluoride undergo a fluorination reaction in water to produce fluoroethanesulfonyl fluoride (e.g., in the literature Toxic Fluorine Compounds. VIII. w-Fluoroalkanesulfonyl Chlorides and Fluorides). Problems with this process include long reaction times, incomplete consumption of raw materials, numerous byproducts, extremely low yield, and low product purity, making it unsuitable for industrial production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing fluoroethane sulfonyl fluoride, which has simple steps, convenient operation, mild reaction, high product yield, high purity, and is suitable for industrial promotion.

[0005] To achieve the above objectives, the technical solution adopted by this invention is as follows: a method for preparing fluoroethanesulfonyl fluoride, comprising the following steps: 1. Dissolving chloroethanesulfonyl chloride in an organic solvent, adding a phase transfer catalyst, an iodide salt catalyst, and an acidic fluorinating reagent, and heating to carry out a fluorination reaction; wherein the organic solvent is selected from one of diethyl ether, methyl tert-butyl ether, tetrahydrofuran, ethyl acetate, dimethyl carbonate, and acetonitrile; the iodide salt catalyst is selected from one of potassium iodide and sodium iodide; the acidic fluorinating reagent is selected from one of triethylamine trihydrofluoride, ammonium bifluoride, and potassium hydrofluoride; 2. After the reaction is completed, washing the reaction solution with water, evaporating the solvent, and then distilling the concentrated solution to obtain the fluoroethanesulfonyl fluoride product.

[0006] The above reaction is illustrated below: .

[0007] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the phase transfer catalyst is selected from one or more of 18-crown ether-6, benzyltriethylammonium chloride, and tetrabutylammonium bromide; the molar ratio of the phase transfer catalyst to chloroethanesulfonyl chloride is 0.01 to 0.1.

[0008] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the phase transfer catalyst is selected as benzyltriethylammonium chloride, and the molar ratio of benzyltriethylammonium chloride to chloroethanesulfonyl chloride is 0.03.

[0009] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the molar ratio of iodide salt catalyst to chloroethanesulfonyl chloride is 0.05–0.2.

[0010] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the molar ratio of the acidic fluorinating reagent to chloroethanesulfonyl chloride is 2.1–5.

[0011] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the mass ratio of the organic solvent to chloroethanesulfonyl chloride is 3 to 10.

[0012] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the reaction temperature is 25–90°C.

[0013] Furthermore, in the aforementioned method for preparing fluoroethanesulfonyl fluoride, the reaction temperature is 3–12 hours.

[0014] The advantages of this invention are: the preparation method of fluoroethane sulfonyl fluoride described in this invention has few process steps, is simple and easy to operate, has a mild and controllable reaction, simple post-processing, high product yield, high purity, and is suitable for industrial promotion. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to preferred embodiments.

[0016] Example 1: 163g of chloroethane sulfonyl chloride, 815g of dimethyl carbonate, 6.8g of benzyltriethylammonium chloride, 15g of sodium iodide, and 199.5g of ammonium bifluoride were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and kept at 70°C for 6 hours. The reaction was then stopped and cooled to room temperature.

[0017] After washing the reaction solution three times with water, the solution was concentrated to remove dimethyl carbonate, and the concentrate was then distilled to obtain 123g of fluoroethanesulfonyl fluoride. The purity was determined to be 99.95% by GC (gas chromatography), and the molar yield was calculated to be 94.62%.

[0018] Example 2: 163g of chloroethanesulfonyl chloride, 489g of diethyl ether, 26.4g of 18-crown ether-6, 7.5g of sodium iodide, and 390g of potassium hydrofluoric acid were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and kept at 25°C for 12 hours. The reaction was then stopped and cooled to room temperature.

[0019] After washing the reaction solution three times with water, the ether was removed by concentration. The concentrate was then distilled to obtain 115g of fluoroethanesulfonyl fluoride. The purity was determined to be 99.57% by GC (gas chromatography), and the molar yield was calculated to be 88.46%.

[0020] Example 3: 163g of chloroethane sulfonyl chloride, 1630g of dimethyl carbonate, 3.2g of tetrabutylammonium bromide, 30g of sodium iodide, and 338.5g of triethylamine trihydrofluoride were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous, and the reaction was carried out at 90°C for 3 hours. The reaction was then stopped and cooled to room temperature.

[0021] After washing the reaction solution three times with water, the dimethyl carbonate was concentrated to remove it. The concentrate was then distilled to obtain 119g of fluoroethanesulfonyl fluoride. The purity was determined to be 99.83% by GC (gas chromatography), and the molar yield was calculated to be 91.54%.

[0022] Example 4: 163g of chloroethane sulfonyl chloride, 950g of methyl tert-butyl ether, 18g of benzyl triethyl ammonium chloride, 20g of potassium iodide, and 228g of ammonium hydrogen fluoride were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and kept at 45°C for 8 hours. The reaction was then stopped and cooled to room temperature.

[0023] After washing the reaction solution three times with water, the methyl tert-butyl ether was removed by concentration. The concentrate was then distilled to obtain 118g of fluoroethanesulfonyl fluoride, which was found to have a purity of 99.91% by GC (gas chromatography). The molar yield was calculated to be 90.77%.

[0024] Example 5: 163g of chloroethane sulfonyl chloride, 1350g of tetrahydrofuran, 16g of tetrabutylammonium bromide, 25g of sodium iodide, and 486g of triethylamine trihydrofluoride were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous, and the reaction was carried out at 60°C for 5 hours. The reaction was then stopped and cooled to room temperature.

[0025] After washing the reaction solution three times with water, the tetrahydrofuran was removed by concentration. The concentrate was then distilled to obtain 116g of fluoroethanesulfonyl fluoride, which was found to have a purity of 99.78% by GC (gas chromatography). The molar yield was calculated to be 89.23%.

[0026] Example 6: 163g of chloroethanesulfonyl chloride, 800g of ethyl acetate, 10g of benzyltriethylammonium chloride, 30g of potassium iodide, and 180g of ammonium hydrogen fluoride were added to a three-necked kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and kept at 70°C for 7 hours. The reaction was then stopped and cooled to room temperature.

[0027] After washing the reaction solution three times with water, the ethyl acetate was concentrated to remove it. The concentrate was then distilled to obtain 120g of fluoroethanesulfonyl fluoride. The purity was determined to be 99.93% by GC (gas chromatography), and the molar yield was calculated to be 92.31%.

[0028] Example 7: 163g of chloroethanesulfonyl chloride, 800g of acetonitrile, 12g of 18-crown ether-6, 15g of sodium iodide, and 200g of ammonium bifluoride were added to a three-cupred kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and kept at 80°C for 4 hours. The reaction was then stopped and cooled to room temperature.

[0029] After washing the reaction solution three times with water, the acetonitrile was removed by concentration, and the concentrate was distilled to obtain 118.5 g of fluoroethanesulfonyl fluoride. The purity was determined to be 99.74% by GC (gas chromatography), and the molar yield was calculated to be 91.15%.

[0030] Comparative Example 8: 100g of fluoroethane sulfonyl chloride, 110g of potassium hydrofluoric acid, and 110g of deionized water were added to a three-cup jacketed kettle equipped with a thermometer and a stirrer. The mixture was stirred until homogeneous and reacted vigorously at 25°C for 20 hours. The temperature was then raised to 70°C and reacted for 1 hour before the reaction was stopped.

[0031] The reaction solution was diluted with water, extracted with diethyl ether, dried with anhydrous sodium sulfate, concentrated to remove the diethyl ether, and then distilled to obtain 40g of fluoroethanesulfonyl fluoride. The purity was determined to be 93.65% by GC (gas chromatography), and the molar yield was calculated to be 44.94%.

[0032] The experimental results of Comparative Example 8 show that the preparation method of synthesizing fluoroethanesulfonyl chloride by reacting potassium fluoride in water has disadvantages such as long reaction time, low yield, many by-products, and low product purity.

[0033] As can be seen from the above embodiments, the preparation method of fluoroethane sulfonyl fluoride of the present invention has few process steps, is simple and easy to operate, has a mild and controllable reaction, simple post-processing, high product yield, high purity, and is suitable for industrial promotion.

Claims

1. A method for preparing fluoroethane sulfonyl fluoride, characterized in that: Includes the following steps: I. Dissolve chloroethanesulfonyl chloride in an organic solvent, add a phase transfer catalyst, an iodide catalyst, and an acidic fluorinating reagent, and heat to carry out a fluorination reaction; the organic solvent is selected from one of diethyl ether, methyl tert-butyl ether, tetrahydrofuran, ethyl acetate, dimethyl carbonate, and acetonitrile; the iodide catalyst is selected from one of potassium iodide and sodium iodide; the acidic fluorinating reagent is selected from one of triethylamine trihydrofluoride, ammonium bifluoride, and potassium hydrofluoride; II. After the reaction is completed, wash the reaction solution with water, evaporate the solvent, and distill the concentrated solution to obtain the fluoroethanesulfonyl fluoride product.

2. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The phase transfer catalyst is selected from one or more of 18-crown ether-6, benzyltriethylammonium chloride, and tetrabutylammonium bromide; the molar ratio of the phase transfer catalyst to chloroethanesulfonyl chloride is 0.01 to 0.

1.

3. The method for preparing fluoroethane sulfonyl fluoride according to claim 2, characterized in that: The phase transfer catalyst used is benzyltriethylammonium chloride, and the molar ratio of benzyltriethylammonium chloride to chloroethanesulfonyl chloride is 0.

03.

4. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The molar ratio of iodized salt catalyst to chloroethane sulfonyl chloride is 0.05–0.

2.

5. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The molar ratio of the acidic fluorinating reagent to chloroethanesulfonyl chloride is 2.1 to 5.

6. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The mass ratio of organic solvent to chloroethanesulfonyl chloride is 3 to 10.

7. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The reaction temperature is 25–90°C.

8. The method for preparing fluoroethane sulfonyl fluoride according to claim 1, characterized in that: The reaction temperature is 3 to 12 hours.