A method for preparing sulfuryl fluoride

Abstract

The application discloses a preparation method of sulfuryl fluoride, which comprises the following steps: (1) generating sulfonamide by reacting sulfuryl chloride with secondary amine; (2) purifying the sulfonamide and collecting amine hydrochloride; (3) generating sulfuryl fluoride by reacting the sulfonamide with a fluorinated salt; and (4) recovering the secondary amine. The preparation method of the sulfuryl fluoride is simple in synthesis method, low in reaction temperature, simple in operation, low in requirement for equipment, high in synthesis efficiency, free of by-products, and suitable for industrialized scale production as water is used as a solvent.

Description

Technical Field

[0001] This invention relates to a method for preparing thioyl fluoride, and more particularly to a method for preparing high-purity, green, and efficient thioyl fluoride. Background Technology

[0002] Thionyl fluoride, with the chemical formula SO₂F₂, is a colorless and odorless gas at room temperature. It is a commonly used industrial fumigant, widely available and extremely inexpensive. In the presence of an alkaline environment, thioyl fluoride is the simplest and cheapest method for preparing fluorosulfonic acid compounds.

[0003] In recent years, Sharpless et al. have reported the use of "SF" click chemistry to efficiently synthesize a series of sulfonic acids and yellow amide compounds, which have significant application value in the pharmaceutical and new materials fields. In the pharmaceutical field, it is applied to the deoxyfluorination of phenol, the preparation of aryl fluorosulfonates using yellow acyl diethers as a precursor, stable fluorothioylation reagents, metal-catalyzed boric acid coupling reactions, and metal-catalyzed CN bond coupling reactions.

[0004] In the field of polymer materials, thioyl fluoride is an important raw material for the synthesis of polysulfate materials. Polysulfates are a new type of polymer material synthesized using cutting-edge click chemistry technology and a green, environmentally friendly, and highly efficient method. Polysulfate materials exhibit excellent comprehensive properties, including good thermal stability, excellent mechanical properties, good dimensional stability, excellent chemical corrosion resistance, and a low dielectric constant. They also demonstrate excellent performance in water treatment membranes. However, current polysulfate materials have relatively low high-temperature performance, low transparency, and poor flame retardancy.

[0005] Current reported methods for preparing sulfuryl fluoride use sulfur dioxide or sulfuryl chloride as the sulfur source and fluoride salts as raw materials. The reaction requires high temperature and pressure conditions, and the addition of special catalysts. These catalysts are too expensive and difficult to recycle. The reaction conditions are harsh, the operation is complex, the equipment requirements are high, the yield is low, and byproducts are generated, requiring separation operations such as gas washing or distillation. This results in high energy consumption, significant waste generation, and environmental pollution, and the operation is complex.

[0006] Therefore, there is an urgent need to provide a simple method for preparing thioyl fluoride that requires minimal equipment. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing thioyl fluoride. This method is simple to operate, has low requirements for equipment, is more flexible and safe in equipment selection and use, has no side reactions, the reaction rate is easy to control, the product has high purity, and uses water as a solvent, making it more suitable for industrial production scale-up.

[0008] To achieve the above objectives, the present invention provides a method for preparing thioyl fluoride, the method comprising the following steps:

[0009] (1) Sulfonamide is generated by the reaction of thioyl chloride and secondary amine: the secondary amine is dissolved in an organic solvent to obtain an organic solution of the secondary amine. Under low temperature conditions, thioyl chloride is slowly added dropwise to the organic solution of the secondary amine, stirred and reacted to generate amine hydrochloride and sulfonamide. The amine hydrochloride is filtered and the organic solvent is recovered to obtain sulfonamide.

[0010] (2) Purification of sulfonamide: The sulfonamide was slurried and washed with purified water, the aqueous phase was filtered, and dried to obtain purified sulfonamide;

[0011] (3) The reaction of sulfonamide and fluoride salt to produce sulfuryl fluoride: The purified sulfonamide and water are heated in a water bath, and an aqueous solution of fluoride salt is slowly added dropwise under stirring to produce sulfuryl fluoride.

[0012] (4) Recovery of secondary amine: Dissolve the amine hydrochloride from step (1) in the aqueous phase after filtration in step (2), add an inorganic base to neutralize, and extract the aqueous phase with an extractant to recover the secondary amine.

[0013] In one embodiment, in step (1), the secondary amine is a closed-ring, heterocyclic, or straight-chain form, selected from the following structures:

[0014]

[0015] Where n is an integer greater than or equal to 1; R, R1, and R2 may be the same or different, and are independently selected from hydrogen, halogen, carbonyl, carboxyl, nitro, aliphatic hydrocarbon, or aromatic hydrocarbon; Y is a heteroatom, which is selected from C, S, O, or N.

[0016] In one embodiment, in step (1), the organic solvent is at least one selected from dichloromethane, dichloroethane, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, toluene, ethanol, methanol, hexaoxide, chloroform, diethyl ether, and petroleum ether, with dichloromethane being preferred.

[0017] In one embodiment, in step (1), the reaction temperature is -20℃ to 15℃ and the time is 8 to 16 hours.

[0018] In one embodiment, in step (1), the molar ratio of the secondary amine to the thioyl chloride is 4:1-5.5:1, preferably 4.5:1.

[0019] In one embodiment, in step (4), the inorganic base is at least one of sodium carbonate, sodium bicarbonate, lithium carbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, calcium oxide, magnesium oxide, calcium hydroxide, and potassium hydroxide.

[0020] In one embodiment, in step (3), the fluoride salt is at least one of sodium fluoride, potassium fluoride, sodium hydrofluoride, potassium hydrofluoride, hydrogen fluoride, ammonium fluoride, and triethylamine trifluoride.

[0021] In one embodiment, in step (3), the molar ratio of the fluoride salt and the thioyl chloride is 2:1-4.5:1, preferably 2.5:1.

[0022] In one embodiment, in step (3), the mass fraction of the fluoride salt in the aqueous solution of the fluoride salt is 10%-50%, preferably 15%.

[0023] In one embodiment, in step (3), the reaction temperature is -5℃ to 90℃ and the time is 4 to 10 hours.

[0024] In one embodiment, in step (3), a catalyst is added to the reaction, the catalyst being at least one of formic acid, acetic acid, trifluoroacetic acid, aqueous hydrofluoric acid, trifluoromethanesulfonic acid, sulfuric acid, aluminum trichloride, ferric chloride, and zinc chloride.

[0025] In one embodiment, in step (3), the molar ratio of the catalyst to the sulfonamide is 0-5.0, preferably 4.0.

[0026] In one embodiment, in step (3), the mass ratio of the sulfonamide to water is 1:1.5-1:5.

[0027] In one embodiment, in step (4), the extractant is at least one of dichlorohexane, toluene, ethyl acetate, chloroform, and diethyl ether.

[0028] The preparation method of thioacryl fluoride of the present invention uses readily available and simple raw materials, and the secondary amine can be reused. The reaction temperature is low, the reaction is easy to control, there are no by-products, the selection of equipment and the synthesis operation are flexible, and water is selected as the reaction solvent, making the reaction process safer and greener, and no waste gas is generated. Attached Figure Description

[0029] Figure 1 The image shows the 1H NMR spectrum of sulfonyl dipyrrole in Example 1.

[0030] Figure 2 The image shows the 1H NMR spectrum of sulfonyl dipyrazole in Example 2.

[0031] Figure 3 The image shows the 1H NMR spectrum of sulfonyl dioxazolidine in Example 3.

[0032] Figure 4 The image shows the 1H NMR spectrum of sulfonyl diimidazole in Example 4.

[0033] Figure 5 The image shows the 1H NMR spectrum of sulfonyl dipiperidine in Example 5.

[0034] Figure 6 The image shows the 1H NMR spectrum of sulfonyl di(dihydropyridine) in Example 6.

[0035] Figure 7 The image shows the 1H NMR spectrum of sulfonyldimethylimidazolium in Example 7.

[0036] Figure 8 The 1H NMR spectrum of sulfonyl di(diethylamine) in Example 8 is shown.

[0037] Figure 9 The 1H NMR spectrum of sulfonyl dibenzimidazole in Example 9 is shown.

[0038] Figure 10 The image shows the gas phase spectrum of sulfuryl fluoride gas, based on the national standard GB / T 38211-2019. Detailed Implementation

[0039] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0040] Example 1:

[0041] Preparation of sulfonyl dipyrrole:

[0042] The reaction route of sulfonyl dipyrrole is as follows:

[0043]

[0044] 11.7 kg of pyrrole and 35 L of dichloromethane were added to a 100 L enamel-lined reactor. Stirring was started, and the reactor jacket was circulated with chilled water to cool it to -20 °C. 5 kg of thiocyanate chloride and 35 L of dichloromethane were added to a dropping tank. After the reactor temperature dropped, the solution was slowly added dropwise over 4 hours. After the addition was complete, the chilled water was replaced with tap water, and the mixture was stirred. After 8 hours of reaction, the reaction solution was discharged and centrifuged and filtered to collect 7.7 kg of solid pyrrole hydrochloride. The solvent and product were separated by evaporation of the filtrate. The product, sulfonyl dipyrrole, was slurried and filtered with pure water, and dried for later use. 6.5 kg of sulfonyl dipyrrole salt was collected, with a yield of 90% and a purity of 99.5%.

[0045] Preparation of sulfuryl fluoride gas:

[0046] The reaction route for sulfuryl fluoride is as follows:

[0047]

[0048] 2 kg of sulfonyl dipyrrole salt and 3 L of pure aqueous solution were added to a 10 L PTFE-lined reactor. The reactor jacket was heated to 50 °C with hot water. 1 kg of hydrogen fluoride aqueous solution (40% by mass) was added to a dropping tank. The hydrogen fluoride aqueous solution was added slowly and the reaction was carried out for 6 h. The sulfuryl fluoride gas was compressed and collected at the gas outlet using a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 0.98 kg, with a yield of 95%.

[0049] Pyrrole recovery:

[0050] 7.7 kg of pyrrole hydrochloride was added to an enamel-lined reactor, along with 20 L of deionized water and 4 kg of sodium carbonate aqueous solution. The mixture was stirred and reacted for 6 h. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry pyrrole and filtration. The aqueous phase was evaporated until solid precipitated, and then washed with ethyl acetate. The organic phase was collected, and pyrrole was separated by distillation. 5.8 kg of pyrrole was collected, with a recovery rate of 90%.

[0051] Example 2:

[0052] Preparation of sulfonyl dipyrazole:

[0053] The reaction route for sulfonyl dipyrazole is as follows:

[0054]

[0055] 11.7 kg of pyrazole and 35 L of dichloromethane were added to a 100 L enamel-lined reactor. Stirring was started, and the reactor jacket was circulated with chilled water to cool it to -2 °C. 5 kg of thioyl chloride and 35 L of dichloromethane were added to a dropping tank. After the reactor temperature dropped, the solution was slowly added dropwise over 4 hours. After the addition was complete, the chilled water was replaced with tap water, and the mixture was stirred. After 8 hours of reaction, the reaction solution was discharged and centrifuged and filtered to collect the solid pyrazole hydrochloride. The solvent and product were separated by evaporation of the filtrate. The product, sulfonyl dipyrazole, was slurried and filtered with pure water, and then dried for later use. 6.0 kg of sulfonyl dipyrazole salt was collected, with a yield of 82% and a purity of 99.2%.

[0056] Preparation of sulfuryl fluoride gas:

[0057] The reaction route for sulfuryl fluoride is as follows:

[0058]

[0059] 2 kg of sulfonyl dipyrazole salt, 3 L of pure aqueous solution, and 0.4 kg of trifluoroacetic acid were added to a 10 L PTFE-lined reactor. The reactor jacket was heated to 30 °C with hot water. 1.45 kg of potassium fluoride aqueous solution (30% by mass) was added to a dropping tank. The potassium fluoride aqueous solution was slowly added dropwise. The sulfuryl fluoride gas was compressed and collected at the gas outlet using a gas compression pump.

[0060] Pyrazole recovery:

[0061] 8.2 kg of pyrazole hydrochloride was added to an enamel-lined reactor, along with 30 L of deionized water and 4.5 kg of sodium carbonate aqueous solution. The mixture was stirred and reacted for 6 h. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry pyrazole and filtration. The aqueous phase was evaporated until solid precipitated, and then washed with ethyl acetate. The organic phase was collected, and pyrazole was separated by distillation. 6 kg of pyrrole was collected, with a recovery rate of 90%.

[0062] Example 3:

[0063] Preparation of sulfonyl dioxazolidine:

[0064] The reaction route of sulfonyl dioxazolidine is as follows:

[0065]

[0066] 12.5 kg of oxazolidine and 35 L of dichloromethane were added to a 100 L ceramic reactor. Stirring was started, and the reactor jacket was circulated with chilled water to cool it to -15 °C. 5 kg of thiocyanate chloride and 35 L of dichloromethane were added to a dropping tank. After the reactor temperature dropped, the solution was slowly added dropwise over 4 hours. After the addition was complete, the chilled water was replaced with tap water, and the mixture was stirred. After 5 hours of reaction, the reaction solution was discharged and centrifuged and filtered to collect the solid phase of oxazolidine hydrochloride. The solvent and product were separated by evaporation of the filtrate. The product, dioxazolidine sulfonate, was slurried and filtered with pure water to obtain the aqueous phase, dried, and stored for later use. 6 kg of dioxazolidine sulfonate was collected, with a yield of 78% and a purity of 99.5%.

[0067] Preparation of sulfuryl fluoride gas:

[0068] The reaction route for sulfuryl fluoride is as follows:

[0069]

[0070] 2 kg of sulfonyl dioxazolidine salt and 3 L of pure aqueous solution were added to a 10 L PTFE-lined reactor. The reactor jacket was heated to 20 °C with hot water. 1.2 kg of hydrogen fluoride aqueous solution (hydrogen fluoride aqueous solution mass fraction of 40%) was added to the dropping tank. The hydrogen fluoride aqueous solution was slowly added dropwise. The sulfuryl fluoride gas was compressed and collected at the gas outlet by a gas compression pump.

[0071] Recovery of oxazolidine:

[0072] 7.8 kg of pyrazole hydrochloride was added to an enamel-lined reactor, along with 30 L of deionized water and 5 kg of sodium carbonate aqueous solution. The mixture was stirred and reacted for 10 h. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry filtration of sulfonyl dioxazolidine. The aqueous phase was evaporated until solid precipitated, and then washed with ethyl acetate. The organic phase was collected, and oxazolidine was separated by distillation. 6 kg of oxazolidine was collected, with a recovery rate of 80%.

[0073] Example 4:

[0074] Preparation of sulfonyl diimidazole:

[0075] The reaction route of sulfonyl diimidazole is as follows:

[0076]

[0077] 124 kg of imidazole and 400 kg of 1,2-dichloroethane were added to a 1-ton reactor. Stirring was started, and the reactor was cooled to -5°C using a jacket. 60 kg of sulfuryl chloride and 200 kg of 1,2-dichloroethane were added to a dropping tank. After the reactor temperature dropped, sulfuryl chloride was slowly added dropwise over 1 hour. After the addition was completed, the cooling of the reactor was stopped, and the reaction continued for 10 hours. The reaction solution was discharged, and imidazole hydrochloride was filtered out by centrifugation. 47 kg of solid imidazole hydrochloride was collected. The filtrate was separated into sulfonyl diimidazole by distillation. The sulfonyl diimidazole was then slurried with water, filtered, dried, and 88 kg of sulfonyl diimidazole was collected, with a yield of 95% and a purity of 99.5%.

[0078] Preparation of sulfuryl fluoride gas:

[0079] The reaction route for sulfuryl fluoride is as follows:

[0080]

[0081] 88 kg of diimidazole sulfonic acid salt and 50 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 30 °C by water. 45 kg of hydrofluoric acid aqueous solution (40% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was slowly added dropwise to control the reaction rate. The reaction was carried out for 8 hours. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 45 kg, the yield was 98%, and the purity was 99.5%.

[0082] Imidazole recovery:

[0083] 47 kg of imidazole hydrochloride was added to a reaction vessel, along with 50 kg of purified water and 24 kg of sodium carbonate. The mixture was stirred for 8 hours. After the reaction was completed, it was mixed with the aqueous phase obtained by slurry sulfonyl diimidazole and filtered. The mixture was evaporated until solid precipitated. The system was then washed with ethanol, and the liquid phase was collected. The imidazole was separated by distillation, and 60 kg of imidazole was collected, with a yield of 90%.

[0084] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with sodium carbonate, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain distilled imidazole with a mass of 60 kg and a recovery rate of 98%.

[0085] Example 5:

[0086] Preparation of sulfonylpiperidine:

[0087] The reaction route of sulfonyl dipiperidine is as follows:

[0088]

[0089] 100 kg of piperidine and 400 kg of 1,2-dichloroethane were added to a 1-ton reactor. Stirring was started, and the reactor was cooled to -10°C using a jacket. 50 kg of sulfuryl chloride and 200 kg of 1,2-dichloroethane were added to a dropping tank. After the reactor temperature dropped, sulfuryl chloride was slowly added dropwise over 5 hours. After the addition was completed, the cooling of the reactor was stopped, and the reaction continued for 10 hours. The reaction solution was discharged, and piperidine hydrochloride was filtered out by centrifugation. 55 kg of solid piperidine hydrochloride was collected. The filtrate was separated into sulfonyl dipiperidine by distillation. The sulfonyl dipiperidine was then slurried with water, filtered, dried, and 68 kg of sulfonyl dipiperidine was collected, with a yield of 85% and a purity of 99.5%.

[0090] Preparation of sulfuryl fluoride gas:

[0091] The reaction route for sulfuryl fluoride is as follows:

[0092]

[0093] 60 kg of sulfonyl dipiperidine salt and 50 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 30 °C by water. 40 kg of hydrofluoric acid aqueous solution (50% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was slowly added dropwise to control the reaction rate. The reaction was carried out for 10 h. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 30 kg, the yield was 88%, and the purity was 99.5%.

[0094] Piperidine recovery:

[0095] Add 55 kg of imidazole hydrochloride to the reaction vessel, add 50 kg of purified water and 30 kg of sodium carbonate, stir for 8 hours. After the reaction is complete, mix with the aqueous phase after slurrying and filtration of sulfonyl piperidine, evaporate until solid precipitates in the system, wash with ethanol, collect the liquid phase, separate piperidine by distillation, collect 50 kg of piperidine, with a yield of 80%.

[0096] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with sodium carbonate, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain piperidine with a mass of 40 kg and a recovery rate of 70%.

[0097] Example 6:

[0098] Preparation of sulfonyl di(dihydropyridine):

[0099] The reaction route for sulfonyl di(dihydropyridine) is as follows:

[0100]

[0101] Add 90 kg of dihydropiperidine and 300 kg of chloroform to a 1-ton reactor and start stirring. Cool the reactor to 0°C using a jacket. Add 400 kg of thioyl chloride and 100 kg of chloroform to a dropping tank. After the reactor temperature drops, slowly add thioyl chloride over 2 hours. After the addition is complete, stop cooling the reactor and continue the reaction for another 2 hours. Discharge the reaction liquid and filter out dihydropyridine hydrochloride using a centrifuge. Collect 50 kg of solid dihydropyridine hydrochloride. Separate the product sulfonyl di(dihydropyridine) from the filtrate by distillation. Pulp the sulfonyl di(dihydropyridine) with water, filter and dry. Collect 50 kg of sulfonyl di(dihydropyridine), with a yield of 75% and a purity of 99.5%.

[0102] Preparation of sulfuryl fluoride gas:

[0103] The reaction route for sulfuryl fluoride is as follows:

[0104]

[0105] 50 kg of sulfonyl di(dihydropyridine) salt and 50 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 60 °C by water. 80 kg of hydrofluoric acid aqueous solution (10% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was slowly added dropwise to control the reaction rate. The reaction was carried out for 10 h. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 20 kg, the yield was 78%, and the purity was 99.5%.

[0106] Dihydropyridine recovery:

[0107] 45 kg of imidazole hydrochloride was added to a reaction vessel, along with 50 kg of purified water and 20 kg of calcium oxide. The mixture was stirred for 8 hours. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry bis(dihydropyridine). The mixture was evaporated until solid precipitates. The system was then washed with ethanol, and the liquid phase was collected. Dihydropyridine was separated by distillation, and 40 kg of dihydropyridine was collected, with a yield of 90%.

[0108] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with calcium oxide, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain dihydropyridine with a mass of 30 kg and a recovery rate of 70%.

[0109] Example 7:

[0110] Preparation of sulfonyldimethylimidazole:

[0111] The reaction route of sulfonyldimethylimidazole is as follows:

[0112]

[0113] 90 kg of methylimidazole and 300 kg of methanol were added to a 1-ton reactor. Stirring was started, and the reactor was cooled to -20°C using a jacket. 40 kg of sulfuryl chloride and 100 kg of methanol were added to a dropping tank. After the reactor temperature dropped, sulfuryl chloride was slowly added dropwise over 8 hours. After the addition was completed, the cooling of the reactor was stopped, and the reaction continued for another 8 hours. The reaction liquid was discharged, and the hydrochloride was filtered out by centrifugation. 60 kg of solid methylimidazole hydrochloride was collected. The filtrate was separated into sulfonyl dimethylimidazole by distillation. The sulfonyl dimethylimidazole was then pulped with water, filtered, dried, and 50 kg of sulfonyl dimethylimidazole was collected. The yield was 85%, and the purity was 99.5%.

[0114] Preparation of sulfuryl fluoride gas:

[0115] The reaction route for sulfuryl fluoride is as follows:

[0116]

[0117] 50 kg of sulfonyl dimethyl imidazole salt and 50 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 50 °C by water. 40 kg of hydrofluoric acid aqueous solution (50% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was slowly added dropwise to control the reaction rate. The reaction was carried out for 5 hours. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 40 kg, the yield was 88%, and the purity was 99.5%.

[0118] Methylimidazole recovery:

[0119] 60 kg of methylimidazolium hydrochloride was added to a reaction vessel, along with 50 kg of purified water and 20 kg of potassium carbonate. The mixture was stirred for 8 hours. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry sulfonyl dimethylimidazolium and filtered. The mixture was evaporated until solid precipitates. The system was then washed with ethanol, and the liquid phase was collected. Methylimidazolium was separated by distillation, and 40 kg of methylimidazolium was collected, with a yield of 90%.

[0120] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with potassium carbonate, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain distilled methylimidazole with a mass of 30 kg and a recovery rate of 80%.

[0121] Example 8:

[0122] Preparation of sulfonyl di(diethylamine):

[0123] The reaction route for sulfonyl di(diethylamine) is as follows:

[0124]

[0125] 100 kg of diethylamine and 400 kg of 1,2-dichloroethane were added to a 1-ton reactor. Stirring was started, and the reactor was cooled to -5°C using a jacket. 60 kg of thiocyanate chloride and 200 kg of 1,2-dichloroethane were added to a dropping tank. After the reactor temperature dropped, thiocyanate chloride was slowly added dropwise over 1 hour. After the addition was completed, the cooling of the reactor was stopped, and the reaction continued for 10 hours. The reaction solution was discharged, and diethylamine hydrochloride was filtered out by centrifugation. 47 kg of solid diethylamine hydrochloride was collected. The filtrate was separated into sulfonyl di(diethylamine) by distillation. The sulfonyl di(diethylamine) was then pulped with water, filtered, dried, and 88 kg of sulfonyl di(diethylamine) was collected, with a yield of 95% and a purity of 99.5%.

[0126] Preparation of sulfuryl fluoride gas:

[0127] The reaction route for sulfuryl fluoride is as follows:

[0128]

[0129] 88 kg of di(diethylamine) sulfonate salt and 50 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 30 °C by water. 45 kg of hydrofluoric acid aqueous solution (40% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was slowly added dropwise to control the reaction rate. The reaction was carried out for 8 hours. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 45 kg, the yield was 98%, and the purity was 99.5%.

[0130] Diethylamine recovery:

[0131] 47 kg of imidazole hydrochloride was added to a reaction vessel, along with 50 kg of purified water and 24 kg of sodium carbonate. The mixture was stirred for 8 hours. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurrying and filtering sulfonyl di(diethylamine). The mixture was evaporated until solid precipitated. The system was then washed with ethanol, and the liquid phase was collected. Diethylamine was separated by distillation, and 60 kg of diethylamine was collected, with a yield of 90%.

[0132] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with sodium carbonate, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain diethylamine after distillation. The mass of diethylamine was 60 kg, and the recovery rate was 98%.

[0133] Example 9:

[0134] Preparation of sulfonyl dibenzimidazole:

[0135] The reaction route of sulfonyl dibenzimidazole is as follows:

[0136]

[0137] 100 kg of benzimidazole and 400 kg of 1,2-dichloroethane were added to a 1-ton reactor. Stirring was started, and the reactor was cooled to 5°C using a jacket. 58 kg of sulfuryl chloride and 200 kg of 1,2-dichloroethane were added to a dropping tank. After the reactor temperature decreased, sulfuryl chloride was slowly added dropwise over 1 hour. After the addition was completed, the cooling of the reactor was stopped, and the reaction continued for 10 hours. The reaction liquid was discharged, and benzimidazole hydrochloride was filtered out by centrifugation. 66 kg of solid benzimidazole hydrochloride was collected. The filtrate was separated into sulfonyl dibenzimidazole by distillation. The sulfonyl dibenzimidazole was then slurried with water, filtered, dried, and 128 kg of sulfonyl benzimidazole was collected, with a yield of 95% and a purity of 99.5%.

[0138] Preparation of sulfuryl fluoride gas:

[0139] The reaction route for sulfuryl fluoride is as follows:

[0140]

[0141] 128 kg of benzimidazole sulfonic acid salt and 100 kg of water were added to a 1000 L PTFE-lined reactor. The reactor jacket was heated to 80 °C by water. 45 kg of hydrofluoric acid aqueous solution (50% by mass) was added to a dropping tank. The hydrofluoric acid aqueous solution was added slowly to control the reaction rate. The reaction was carried out for 8 hours. The sulfuryl fluoride gas was collected at the gas outlet by a gas compression pump. The mass of the obtained sulfuryl fluoride gas was 45 kg, the yield was 98%, and the purity was 99.5%.

[0142] Benzimidazole recovery:

[0143] 66 kg of imidazole hydrochloride was added to a reaction vessel, along with 50 kg of purified water and 24 kg of sodium carbonate. The mixture was stirred for 8 hours. After the reaction was completed, the mixture was mixed with the aqueous phase obtained by slurry sulfonyl dibenzimidazole and filtered. The mixture was evaporated until solid precipitated. The system was then washed with ethanol, and the liquid phase was collected. Benzimazole was separated by distillation, and 60 kg of benzimidazole was collected, with a yield of 90%.

[0144] The aqueous solution obtained during the preparation of sulfuryl fluoride gas was collected, neutralized with sodium carbonate, and after neutralization, the aqueous phase was evaporated, inorganic salts were filtered, and the aqueous phase was concentrated and distilled to finally obtain distilled benzimidazole with a mass of 35 kg and a recovery rate of 98%.

[0145] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing thioyl fluoride, characterized in that, Includes the following steps: (1) Sulfonamide is generated by the reaction of thioyl chloride and secondary amine: the secondary amine is dissolved in an organic solvent to obtain an organic solution of the secondary amine. Under low temperature conditions, thioyl chloride is slowly added dropwise to the organic solution of the secondary amine, stirred and reacted to generate amine hydrochloride and sulfonamide. The amine hydrochloride is filtered and the organic solvent is recovered to obtain sulfonamide. (2) Purification of sulfonamide: The sulfonamide was slurried and washed with purified water, the aqueous phase was filtered, and dried to obtain purified sulfonamide; (3) The reaction of sulfonamide and fluoride salt to produce sulfuryl fluoride: The purified sulfonamide and water are heated in a water bath, and an aqueous solution of fluoride salt is slowly added dropwise under stirring to produce sulfuryl fluoride. (4) Recovery of secondary amine: Dissolve the amine hydrochloride from step (1) in the aqueous phase after filtration in step (2), add an inorganic base to neutralize, and extract the aqueous phase with an extractant to recover the secondary amine; In step (1), the secondary amine is a closed-ring, heterocyclic, or straight-chain form, selected from the following structures: Where n is an integer greater than or equal to 1; R, R1, and R2 may be the same or different, and are independently selected from hydrogen, halogen, carbonyl, carboxyl, nitro, aliphatic hydrocarbon, or aromatic hydrocarbon; Y is a heteroatom, which is selected from C, S, O, or N; In step (3), the fluoride salt is at least one of sodium fluoride, potassium fluoride, sodium hydrofluoride, potassium hydrofluoride, and hydrogen fluoride.

2. The preparation method according to claim 1, characterized in that, In step (1), the organic solvent is at least one of dichloromethane, dichloroethane, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, toluene, ethanol, methanol, hexaoxide, chloroform, diethyl ether, and petroleum ether.

3. The preparation method according to claim 1, characterized in that, In step (1), the reaction temperature is -20℃ to 15℃ and the time is 8 to 16 hours.

4. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of the secondary amine to thiocyanate is 4:1-5.5:

1.

5. The preparation method according to claim 1, characterized in that, In step (3), the mass ratio of sulfonamide to water is 1:1.5-1:5, the molar ratio of fluoride salt to sulfuryl chloride is 2:1-4.5:1, and the mass fraction of fluoride salt in the aqueous solution of fluoride salt is 10%-50%.

6. The preparation method according to claim 1, characterized in that, In step (3), the reaction temperature is -5℃ to 90℃ and the time is 4 to 10 hours.

7. The preparation method according to claim 1, characterized in that, In step (3), a catalyst is added to the reaction, and the catalyst is at least one of formic acid, acetic acid, trifluoroacetic acid, hydrofluoric acid aqueous solution, trifluoromethanesulfonic acid, sulfuric acid, aluminum trichloride, ferric chloride, and zinc chloride.

8. The preparation method according to claim 7, characterized in that, In step (3), the molar ratio of the catalyst to sulfonamide is 0-5.

0.

9. The preparation method according to claim 1, characterized in that, In step (4), the inorganic base is at least one of sodium carbonate, sodium bicarbonate, lithium carbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, calcium oxide, magnesium oxide, calcium hydroxide, and potassium hydroxide; in step (4), the extractant is at least one of dichlorohexane, toluene, ethyl acetate, chloroform, and diethyl ether.

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