A trifluoromethylsulfonyl fluoride and its preparation method and apparatus

Abstract

This invention relates to the field of fine chemicals, specifically to a trifluoromethanesulfonyl fluoride and its preparation method and apparatus. The method for preparing trifluoromethanesulfonyl fluoride provided by this invention includes the following steps: mixing a solution containing fluoride, hydrochloric acid, a phase transfer catalyst, and methanethiol to obtain a mixed solution; subjecting the mixed solution to an electrochemical fluorination reaction and condensing it to obtain trifluoromethanesulfonyl fluoride; wherein, the gaseous product generated in the electrochemical fluorination reaction is directly returned to the mixed solution after condensation to continue the reaction. The preparation method of this invention uses readily available raw materials, has low cost, and high yield; it does not involve the handling of highly toxic or hazardous gases; the reaction is green and mild, safe and controllable, and suitable for large-scale production.

Description

Technical Field

[0001] This invention relates to the field of fine chemicals, specifically to a trifluoromethylsulfonyl fluoride and its preparation method and apparatus. Background Technology

[0002] Trifluoromethanesulfonyl fluoride (CF3SO2F) is an important fluorine-containing organic chemical intermediate. It can be used as an end-product in environmentally friendly insulating gases and semiconductor manufacturing, and also as a crucial intermediate in organic synthesis in lithium-ion battery electrolytes and pharmaceuticals. In lithium-ion battery electrolytes, it serves as a key raw material for semi-solid and solid-state lithium-ion battery electrolytes such as lithium difluorosulfonylimide. In drug synthesis, compounds containing the trifluoromethanesulfonyl fluoride structure often exhibit unique biological activities and pharmacological properties, making them suitable for the development of novel drugs. Furthermore, with the national promotion of environmentally friendly materials, trifluoromethanesulfonyl fluoride, as a substitute for sulfur hexafluoride, is increasingly becoming a hot product in the field of fluorine-containing fine chemicals.

[0003] Currently, the main methods for preparing trifluoromethanesulfonyl fluoride include: direct fluorination, which involves the direct reaction of methanesulfonyl halides with fluorine gas; this method involves highly toxic gases, the reaction is violent and difficult to control, and it is highly dangerous; fluorine-halogen exchange, which involves preferentially synthesizing trifluoromethanesulfonyl chloride and then reacting it with fluorides for fluorination; this method has low atom utilization, complex steps, high cost, and is not conducive to large-scale production; and traditional electrolytic fluorination, which involves adding methanesulfonyl fluoride and hydrogen fluoride into an electrolytic cell and then adding a conductive agent for electrolytic fluorination; although this method is simple and can be mass-produced, the yield is low, it involves highly toxic gases, and it has high equipment requirements.

[0004] There is a lack of an environmentally friendly, safe, and economical method for preparing trifluoromethanesulfonyl fluoride in the existing technology. Summary of the Invention

[0005] This invention provides a trifluoromethanesulfonyl fluoride and its preparation method and apparatus, to solve the problem of the lack of an environmentally friendly, safe and economical preparation method for trifluoromethanesulfonyl fluoride in the prior art.

[0006] In a first aspect, the present invention provides a method for preparing trifluoromethanesulfonyl fluoride, comprising the following steps: A mixed solution is prepared by mixing a fluoride-containing solution, hydrochloric acid, a phase transfer catalyst, and methanethiol. The mixed solution is then subjected to an electrochemical fluorination reaction and condensed to obtain trifluoromethylsulfonyl fluoride. In this process, the gaseous products generated in the electrochemical fluorination reaction are condensed and then directly returned to the mixed solution to continue the reaction.

[0007] In one alternative embodiment, the mixed solution is prepared by mixing the fluoride with a solvent containing the fluoride, then mixing with hydrochloric acid, then adding a phase transfer catalyst to mix (to dissolve the solid), and then adding methanethiol.

[0008] In one alternative embodiment, the addition of methanethiol includes a process of pre-cooling the methanethiol at a temperature of 0-4°C.

[0009] In one optional embodiment, the fluoride in the fluoride-containing solution is selected from alkali metal fluoride salts; In one optional embodiment, the fluoride in the fluoride-containing solution is selected from at least one of potassium fluoride, sodium fluoride, and cesium fluoride; In one optional embodiment, the solvent in the fluoride-containing solution is selected from polar aprotic solvents; In one optional embodiment, the solvent in the fluoride-containing solution is selected from at least one of acetonitrile, N-methylpyrrolidone, and tetrahydrofuran; In one alternative embodiment, the concentration of HCl in the hydrochloric acid is 1-5 wt%.

[0010] In one alternative embodiment, the phase transfer catalyst is selected from basic polar aprotic reagents; In one alternative embodiment, the phase transfer catalyst is selected from at least one of pyridine, 4-dimethylaminopyridine, and triethylamine.

[0011] In one optional embodiment, the mass ratio of solvent to methanethiol in the fluoride-containing solution is (60-100):1; In one optional embodiment, the molar ratio of fluoride to methanethiol in the fluoride-containing solution is (4-10):1; In one optional embodiment, the volume ratio of the solvent to the hydrochloric acid in the fluoride-containing solution is (0.8-1.2):(0.8-1.2); In one optional embodiment, the molar ratio of the phase transfer catalyst to methanethiol is (0.5-4):1; In one alternative embodiment, the anode electrode material comprises graphite during the electrochemical fluorination reaction. In one alternative embodiment, the cathode electrode material comprises iron during the electrochemical fluorination reaction.

[0012] In one alternative embodiment, the distance between the electrodes in the electrochemical fluorination reaction process is 1-3 cm, for example 1 cm, 2 cm or 3 cm, or within any of the above values.

[0013] In one optional embodiment, the electrode voltage of the electrochemical fluorination reaction is 3.2–4.0 V, and the current density is 8–48 A / m. 2 .

[0014] In one alternative embodiment, the electrochemical fluorination reaction is carried out under a protective gas atmosphere.

[0015] In one alternative embodiment, the protective gas is selected from nitrogen or an inert gas.

[0016] In one alternative embodiment, the inert gas is selected from at least one of helium, neon, and argon.

[0017] In one optional embodiment, the electrochemical fluorination reaction is carried out in the mixed solution at a first temperature, and the gaseous products generated by the reaction are condensed at a second temperature and directly returned to the mixed solution to continue the reaction. In one alternative implementation, the first temperature is 25-35°C; In one alternative embodiment, the second temperature is -45 to -40°C; In one alternative embodiment, the electrochemical fluorination reaction takes 10-50 hours.

[0018] In one alternative embodiment, the condensation temperature after the electrochemical fluorination reaction is -30°C to -25°C.

[0019] In one optional embodiment, the electrochemical fluorination reaction further includes a process for treating the tail gas, wherein the mixed solution undergoes electrochemical fluorination at a first temperature, the gaseous products generated by the reaction are condensed at a second temperature and then directly returned to the mixed solution to continue the reaction, and the uncondensed gas is absorbed by a sodium hydroxide solution and then discharged as tail gas.

[0020] In one alternative embodiment, the sodium hydroxide solution is selected from an aqueous sodium hydroxide solution with a concentration of 2.5-3.5 wt%.

[0021] In one alternative embodiment, the electrochemical fluorination reaction is followed by a quenching reaction process; In one alternative implementation, the quenching agent is water; In one alternative embodiment, the volume ratio of the quencher to the mixed solution is 1:(0.8-1.2).

[0022] Secondly, the present invention provides an apparatus for preparing trifluoromethanesulfonyl fluoride, comprising an electrochemical fluorination reaction tank and a condenser; the electrochemical fluorination reaction tank includes a feed inlet, a gas phase product outlet, and a circulating liquid inlet; the condenser includes a gas phase product inlet and a condensate outlet; wherein the gas phase product outlet is connected to the gas phase product inlet, and the circulating liquid inlet is controllably connected to the condensate outlet.

[0023] Thirdly, the present invention also provides a trifluoromethanesulfonyl fluoride, which is prepared by the preparation method described above.

[0024] The technical solution of this invention has the following advantages: This invention provides a method for preparing trifluoromethanesulfonyl fluoride, comprising the following steps: mixing a solution containing fluoride, hydrochloric acid, a phase transfer catalyst, and methanethiol to obtain a mixed solution; subjecting the mixed solution to an electrochemical fluorination reaction and condensing it to obtain trifluoromethanesulfonyl fluoride; wherein the gaseous product generated in the electrochemical fluorination reaction is directly returned to the mixed solution after condensation to continue the reaction. In this invention, methanethiol is used as a raw material, and fluoride, a phase transfer catalyst, and a conductive agent are added to carry out an electrolytic fluorination reaction, wherein trifluoromethanesulfonyl fluoride is generated at the anode and hydrogen gas is generated at the cathode.

[0025] Furthermore, in this invention, the phase transfer catalyst is selected from basic polar aprotic reagents that can coordinate with chloride and hydrogen ions to ultimately form a fluorinated complex through ion exchange. This complex can serve as a phase transfer catalyst and electron mediator for transferring fluorides to the organic phase, which is beneficial for the contact reaction between the fluorination active intermediate and the substrate, thereby improving the yield of the fluorination reaction. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a diagram of the apparatus for preparing trifluoromethylsulfonyl fluoride according to Example 1 of the present invention; Explanation of reference numerals in the attached figures: 100. Electrochemical fluorination reaction tank; 101. Feed inlet; 102. Gas phase product outlet; 103. Circulating liquid inlet; 200. Condenser; 201. Gas phase product inlet; 202. Condensate outlet; 203. Waste gas outlet; 300. Absorption tank; 301. Waste gas inlet; 400. Finished product storage tank; 401. Finished product inlet. Detailed Implementation The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0028] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0029] The manufacturers and purity of the pharmaceuticals used in the embodiments of this invention are as follows: Methanethiol, purity: 98%, manufacturer: Chengdu Taiyu; Potassium fluoride, purity: 99%, manufacturer: Maclean's Reagents; Pyridine, purity: 99.5%, manufacturer: Maclean's Reagents; Acetonitrile, purity: ≥99.9%, manufacturer: Maclean's Reagents; N-Methylpyrrolidone, ≥99.5%, Manufacturer: Maclean's Reagents; Sodium fluoride, purity: 99%, manufacturer: Maclean's Reagents; Hydrochloric acid, 36.0-38.0 wt%, manufacturer: Sinopharm Group, dilute with deionized water to the target concentration after purchase; Sodium hydroxide, ≥96.0%, Manufacturer: Sinopharm Group.

[0030] In the specific embodiment, the anode electrode material in the electrochemical fluorination reaction tank 100 is graphite; the cathode electrode material is iron; and the electrode working area is 0.00125 m². 2 The voltage for the electrochemical fluorination reaction was 3.2V; the electrode spacing was 1cm; and the temperature for the electrochemical fluorination reaction in the examples and comparative examples was room temperature (25°C).

[0031] Example 1 This invention provides an apparatus for preparing trifluoromethylsulfonyl fluoride, such as... Figure 1 As shown, the device includes an electrochemical fluorination reaction tank 100 and a condenser 200. The electrochemical fluorination reaction tank 100 includes a feed inlet 101, a gaseous product outlet 102, and a circulating liquid inlet 103. The condenser 200 includes a gaseous product inlet 201 and a condensate outlet 202. The gaseous product outlet 102 is connected to the gaseous product inlet 201, and the circulating liquid inlet 103 is controllably connected to the condensate outlet 202.

[0032] In one specific embodiment, the apparatus for preparing trifluoromethanesulfonyl fluoride further includes an absorption tank 300, which includes a waste gas inlet 301; wherein the condenser 200 further includes a waste gas outlet 203, which is connected to the waste gas inlet 301.

[0033] In one specific embodiment, the apparatus for preparing trifluoromethanesulfonyl fluoride further includes a finished product storage tank 400, which includes a finished product inlet 401 and is controllably connected to a condensate outlet 202.

[0034] In another specific embodiment, a second condenser 200 is further included between the condenser 200 and the absorption tank 300, and the second condenser 200 is connected to the exhaust gas outlet 203 and the exhaust gas inlet 301.

[0035] In one embodiment, the electrochemical fluorination reaction tank 100 further includes a stirrer and a protective gas inlet.

[0036] The present invention provides a process for preparing trifluoromethanesulfonyl fluoride using an apparatus in which a fluoride-containing solution, hydrochloric acid, a phase transfer catalyst, and methanethiol are added to an electrochemical fluorination reaction tank 100 through inlet 101. After stirring and mixing, the power is turned on to carry out the electrochemical fluorination reaction. The gaseous product generated in the reaction is output through gaseous product outlet 102 and enters condenser 200 through gaseous product inlet 201. The condensate after condensation is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous product that is not condensed is output through condenser 200 exhaust outlet 203 and enters absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. After the electrochemical fluorination reaction is completed, the gaseous product is condensed and output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401, thus completing the product preparation.

[0037] Experimental Example 2 This embodiment provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, including the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 9.66g of potassium fluoride, then add 1.64g of pyridine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 10mA and maintain the reaction for 12h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction is completed, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser is -45℃ to reduce pollutant emissions.

[0038] The material in the finished product storage tank 400 is: 2.15g of trifluoromethanesulfonyl fluoride with a purity of 97.21% and a theoretical product mass of 3.16g. The calculated overall reaction yield is 68.04%.

[0039] Experimental Example 3 This embodiment provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, including the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 9.66g of potassium fluoride, then add 1.64g of pyridine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 20mA and maintain the reaction for 24h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0040] The material in the finished product storage tank 400 is 2.88g of trifluoromethanesulfonyl fluoride with a purity of 99.13%, and the calculated overall reaction yield is 91.14%.

[0041] Experiment Example 4 This embodiment provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, including the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 7.25g of potassium fluoride, then add 1.64g of pyridine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 20mA and maintain the reaction for 48h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0042] The material in the finished product storage tank 400 is 2.36g of trifluoromethanesulfonyl fluoride with a purity of 98.45%, and the calculated overall reaction yield is 74.68%.

[0043] Experimental Example 5 This embodiment provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, including the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 9.66g of potassium fluoride, then add 1.64g of pyridine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 40mA and maintain the reaction for 12h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0044] The material in the finished product storage tank 400 is 2.71g of trifluoromethanesulfonyl fluoride with a purity of 98.51%, and the calculated overall reaction yield is 85.75%.

[0045] Experimental Example 6 This embodiment provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, including the following steps: S1. Add 80.00g of N-methylpyrrolidone to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 6.98g of sodium fluoride, then add 2.10g of triethylamine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 10mA and maintain the reaction for 12h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0046] The material in the finished product storage tank 400 is 2.21g of trifluoromethanesulfonyl fluoride with a purity of 97.87%, and the calculated overall reaction yield is 69.94%.

[0047] Comparative Example 1 This comparative example provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, comprising the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 9.66g of potassium fluoride. Finally, insert the electrode into the solution, replace the air in the system with nitrogen, seal the system, and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 20mA and maintain the reaction for 24h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0048] The material in the finished product storage tank 400 is: 1.33g of trifluoromethanesulfonyl fluoride with a purity of 96.43% and a theoretical product mass of 3.16g. The calculated overall reaction yield is 42.09%.

[0049] Comparative Example 2 This comparative example provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, comprising the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, add 103.58g of deionized water, and after mixing evenly, add 9.66g of potassium fluoride, then add 1.64g of pyridine. Finally, insert the electrode into the solution, replace the air in the system with nitrogen, seal the system, and keep stirring until the solid is completely dissolved. S2. After pre-cooling methanethiol to 3°C, measure 1.00g and add it to the electrochemical fluorination reaction tank 100 (density: 0.89g / mL, based on the liquid volume after liquefaction of methanethiol). After stirring for 0.5h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 40mA and maintain the reaction for 12h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature: -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0050] The material in the finished product storage tank 400 is: 1.12g of trifluoromethanesulfonyl fluoride with a purity of 96.31% and a theoretical product mass of 3.16g. The calculated overall reaction yield is 35.44%.

[0051] Comparative Example 3 This comparative example provides a method for preparing trifluoromethanesulfonyl fluoride using the apparatus in Example 1, comprising the following steps: S1. Add 80.00g of acetonitrile to the electrochemical fluorination reaction tank 100, start stirring, then slowly add 103.58g of hydrochloric acid (mass percentage of 3.5wt.%), and after mixing evenly, add 9.66g of potassium fluoride, then add 1.64g of pyridine, and finally insert the electrode into the solution. After replacing the air in the system with nitrogen, seal the system and keep stirring until the solid is completely dissolved. S2. Add 2.04 g of 3°C methanesulfonyl fluoride to the electrochemical fluorination reaction tank 100. After stirring for 0.5 h, turn on the power to start the electrochemical fluorination reaction. Set the current value to 10 mA and maintain the reaction for 12 h. The gaseous products generated during electrolysis are condensed by condenser 200 (condensation temperature is -45°C). The condensate is output through condensate outlet 202 and enters the electrochemical fluorination reaction tank 100 through circulation inlet 103 to continue the reaction. The gaseous products that are not condensed are output through condenser 200 exhaust outlet 203 and enter the absorption tank 300 through exhaust inlet 301 before being absorbed and discharged as tail gas. The absorbent in the absorption tank 300 is a 3 wt% sodium hydroxide aqueous solution. After the S3 electrochemical fluorination reaction, the gaseous product is condensed in condenser 200 (condensation temperature -28℃), and the condensate is output through condensate outlet 202 and enters finished product storage tank 400 through finished product inlet 401 to obtain the trifluoromethanesulfonyl fluoride. The electrochemical fluorination reaction also includes disconnecting the power supply and adding an equal volume of deionized water to the electrochemical fluorination reaction tank 100 to quench the reaction. A second condenser 200 is also included between condenser 200 and absorption tank 300. The condensation temperature of the second condenser 200 is -45℃ to reduce pollutant emissions.

[0052] The material in the finished product storage tank 400 is 1.57g of trifluoromethanesulfonyl fluoride with a purity of 97.16%, and the calculated overall reaction yield is 49.68%.

[0053] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing trifluoromethanesulfonyl fluoride, characterized in that, Includes the following steps: A mixed solution is prepared by mixing a fluoride-containing solution, hydrochloric acid, a phase transfer catalyst, and methanethiol. The mixed solution is then subjected to an electrochemical fluorination reaction and condensed to obtain trifluoromethylsulfonyl fluoride. In this process, the gaseous products generated in the electrochemical fluorination reaction are condensed and then directly returned to the mixed solution to continue the reaction.

2. The preparation method according to claim 1, characterized in that, The fluorides in solutions containing fluorides are selected from alkali metal fluoride salts; Preferably, the fluoride in the fluoride-containing solution is selected from at least one of potassium fluoride, sodium fluoride, and cesium fluoride; Preferably, the solvent in the fluoride-containing solution is selected from polar aprotic solvents; Preferably, the solvent in the fluoride-containing solution is selected from at least one of acetonitrile, N-methylpyrrolidone, and tetrahydrofuran.

3. The preparation method according to claim 1 or 2, characterized in that, The concentration of HCl in the hydrochloric acid is 1-5 wt%.

4. The preparation method according to any one of claims 1-3, characterized in that, The phase transfer catalyst is selected from basic polar aprotic reagents; Preferably, the phase transfer catalyst is selected from at least one of pyridine, 4-dimethylaminopyridine, and triethylamine.

5. The preparation method according to any one of claims 1-4, characterized in that, The mass ratio of solvent to methanethiol in a solution containing fluoride is (60-100):1; Preferably, the molar ratio of fluoride to methanethiol in the fluoride-containing solution is (4-10):1; Preferably, the molar ratio of fluoride to methanethiol in the fluoride-containing solution is (6-8):1; Preferably, the volume ratio of the solvent to the hydrochloric acid in the fluoride-containing solution is (0.8-1.2):(0.8-1.2). Preferably, the molar ratio of the phase transfer catalyst to methanethiol is (0.5-4):1; Preferably, the molar ratio of the phase transfer catalyst to methanethiol is (1-2):

1.

6. The preparation method according to any one of claims 1-5, characterized in that, The anode electrode material in the electrochemical fluorination reaction includes graphite. Preferably, the cathode electrode material in the electrochemical fluorination reaction includes iron.

7. The preparation method according to any one of claims 1-6, characterized in that, The electrode voltage for the electrochemical fluorination reaction is 3.2–4.0 V, and the current density is 8–48 A / m. 2 .

8. The preparation method according to any one of claims 1-7, characterized in that, In the electrochemical fluorination reaction, the mixed solution undergoes an electrochemical fluorination reaction at a first temperature, and the gaseous products generated by the reaction are condensed at a second temperature and then directly returned to the mixed solution to continue the reaction. Preferably, the first temperature is 25-35℃; Preferably, the second temperature is -45~-40℃; Preferably, the electrochemical fluorination reaction takes 10-50 hours; Preferably, the condensation temperature after the electrochemical fluorination reaction is -30℃ to -25℃.

9. An apparatus for preparing trifluoromethanesulfonyl fluoride, characterized in that, It includes an electrochemical fluorination reaction tank and a condenser; the electrochemical fluorination reaction tank includes a feed inlet, a gas phase product outlet, and a circulating liquid inlet; the condenser includes a gas phase product inlet and a condensate outlet; wherein the gas phase product outlet is connected to the gas phase product inlet, and the circulating liquid inlet is controllably connected to the condensate outlet.

10. A trifluoromethanesulfonyl fluoride, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

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