Preparation method of alkyl sulfonyl chloride and method for co-producing alkyl sulfonyl chloride and difluorophosphate

Abstract

The invention provides a preparation method of alkyl sulfonyl chloride and a method for co-producing alkyl sulfonyl chloride and difluorophosphate.The preparation method comprises the following steps that alkyl sulfonate and phosphoryl chloride are mixed, a chlorination reaction and aftertreatment are conducted, and alkyl sulfonyl chloride is obtained. According to the preparation method disclosed by the invention, the atom utilization rate is maximized, the process is simple, large-scale industrial production can be realized, a foundation is laid for simultaneously preparing the alkyl sulfonyl chloride and the difluorophosphate, and the production cost of the alkyl sulfonyl chloride and the difluorophosphate is greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of compound synthesis and relates to a method for preparing alkyl sulfonyl chloride and a method for co-producing alkyl sulfonyl chloride and difluorophosphate. Background Art

[0002] Sulfonyl chloride is widely used in the pesticide and pharmaceutical industries, and is used as a raw material for sulfonamide compounds or sulfonic acid compounds in related industries. Fatty sulfonyl chloride is mainly prepared by oxidative chlorination of mercaptans or oxidative chlorination of sulfur-containing derivatives such as thiourea, isothiocyanate, thioacetate, and sulfonate. However, common sulfur-containing compounds have a foul odor and are highly toxic.

[0003] For example, CN 113004175A discloses a method for preparing allyl sulfonyl chloride, comprising the following steps: adding sodium allyl sulfonate, a catalyst, an inhibitor and an inert solvent into a reaction vessel, heating to 80°C to 110°C while stirring, adding thionyl chloride dropwise at the reaction temperature and reacting at the temperature to obtain a reaction solution of allyl sulfonyl chloride, filtering to obtain a filtrate after the reaction, and post-treating the filtrate to obtain the product allyl sulfonyl chloride; the chlorination reagent thionyl chloride used in the method is easily decomposed into toxic gas sulfur dioxide, causing safety and environmental hazards. Therefore, it is necessary to provide an environmentally friendly method with a simple preparation method and capable of industrially producing sulfonyl chloride compounds to overcome the above-mentioned defects.

[0004] In addition, since secondary batteries are important components of energy storage systems in portable electronic devices, power tools, electric vehicles and grid energy storage, their electrolyte solutions include non-aqueous solvents, electrolytes and additives. Difluorophosphates as additives have high electrochemical stability and can improve the conductivity of the electrolyte solution, which can not only improve the low-temperature output characteristics of the battery, but also inhibit the decomposition of the positive electrode surface during high-temperature cycling, and prevent the oxidation reaction of the electrolyte solution, thereby improving the output characteristics and swelling characteristics after high-temperature storage.

[0005] In the prior art, there are many methods for preparing difluorophosphate, and lithium difluorophosphate is mainly prepared by decomposing lithium hexafluorophosphate. For example, CN 101208266A discloses a method for preparing difluorophosphate, in which lithium hexafluorophosphate is reacted with carbonate in a non-aqueous solvent. This method uses expensive lithium hexafluorophosphate and has high production costs. CN 106882782A discloses a method for synthesizing lithium difluorophosphate, in which phosphorus pentoxide, a lithium-containing inorganic salt and phosphorus oxytrifluoride are pressurized and heated in a dry organic solvent to obtain lithium difluorophosphate. This method has harsh reaction conditions and is not conducive to industrial production.

[0006] Based on the above research, it is necessary to provide a method for preparing an alkyl sulfonyl chloride and co-producing difluorophosphate, wherein the method can co-produce a sulfonyl chloride compound and an electrolyte additive difluorophosphate, achieve efficient atomic utilization, and reduce the production costs of the alkyl sulfonyl chloride and difluorophosphate. Summary of the invention

[0007] The present invention aims to provide a method for preparing an alkyl sulfonyl chloride and a method for co-producing an alkyl sulfonyl chloride and a difluorophosphate, and in particular to a method for preparing an allyl sulfonyl chloride and a method for co-producing an allyl sulfonyl chloride and a difluorophosphate. The preparation method achieves maximum atomic utilization, has a simple process and can be industrialized on a large scale, thereby greatly reducing the production costs of the alkyl sulfonyl chloride and the difluorophosphate.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing an alkyl sulfonyl chloride, the preparation method comprising the following steps:

[0010] The alkyl sulfonate is mixed with phosphorus oxychloride, subjected to chlorination reaction and post-treatment, to obtain the alkyl sulfonyl chloride.

[0011] The invention adopts a process for preparing alkyl sulfonyl chloride, in which no solvent is used, raw materials are directly contacted for reaction, the reaction effect is enhanced, a high yield can be achieved without a catalyst, and impurities generated by solvent side reactions are avoided, high-purity alkyl sulfonyl chloride is prepared, and a foundation is laid for the co-production of alkyl sulfonyl chloride and difluorophosphate.

[0012] The reasons for selecting phosphorus oxychloride in the present invention are as follows: (1) since it does not generate toxic gases such as sulfur dioxide, it is environmentally friendly and has a high yield of the product; (2) phosphorus oxychloride can directly react with alkyl sulfonate, so that alkyl sulfonyl chloride can be prepared using only alkyl sulfonate and phosphorus oxychloride, without the need to add other substances such as solvents; (3) solvent side reaction impurities are avoided to obtain high-purity alkyl sulfonyl chloride; (4) the atomic utilization rate can be improved, and the obtained by-product can be used to prepare difluorophosphate, thereby realizing the co-production of two compounds;

[0013] The alkyl sulfonate of the present invention is preferably allyl sulfonate, therefore, allyl sulfonyl chloride and difluorophosphate are preferably co-produced, and the specific reaction equation is as follows:

[0014]

[0015] Wherein, M=Li, Na, K or NH4 + Any one or a combination of at least two of the following.

[0016] Preferably, the molar ratio of the hydrocarbon sulfonate to phosphorus oxychloride is 1:(1-5), for example, 1:1, 1:2, 1:3, 1:4 or 1:5, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Since no solvent is added during the chlorination reaction of the present invention, further increasing the amount of phosphorus oxychloride during the chlorination reaction of the present invention is beneficial to the dispersion of the alkyl sulfonate, but too high an amount will increase the recovery cost of the phosphorus oxychloride.

[0018] Preferably, the alkyl sulfonyl chloride comprises allyl sulfonyl chloride.

[0019] Preferably, the post-treatment comprises: obtaining the alkyl sulfonyl chloride by extraction with a first solvent, filtering and distilling under reduced pressure.

[0020] Preferably, the first solvent includes any one of chain alkanes, cycloalkanes, halogenated alkanes, aromatic hydrocarbons, halogenated aromatic hydrocarbons, carbonates, carboxylates or ether compounds, or a combination of at least two thereof.

[0021] Preferably, the alkane in the first solvent includes any one of n-pentane, cyclopentane, n-hexane or cyclohexane or a combination of at least two thereof; the halogenated alkane includes any one of dichloromethane, chloroform, 1,2-dichloroethane or 1,1,2,2-tetrachloroethane or a combination of at least two thereof; the aromatic hydrocarbon includes toluene and / or xylene; the halogenated aromatic hydrocarbon includes any one of chlorobenzene, dichlorobenzene or trichlorobenzene or a combination of at least two thereof; the carbonate includes dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate or isocyanate. The invention can be any one of propylene esters or a combination of at least two thereof; the carboxylic acid esters include ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, γ-valerolactone or γ-butyrolactone or a combination of at least two thereof; the ether compounds include any one of ethyl ether, isopropyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, anisole or phenethyl ether or a combination of at least two thereof.

[0022] Preferably, the hydrocarbyl sulfonate includes any one of lithium hydrocarbyl sulfonate, sodium hydrocarbyl sulfonate, potassium hydrocarbyl sulfonate or ammonium hydrocarbyl sulfonate, or a combination of at least two thereof.

[0023] In a second aspect, the present invention provides a method for co-producing alkyl sulfonyl chloride and difluorophosphate, the method comprising the following steps:

[0024] Prepared by the preparation method described in the first aspect to obtain alkyl sulfonyl chloride and dichlorophosphate;

[0025] A fluorination agent, a second solvent and the dichlorophosphate are mixed, and a fluorination reaction and post-treatment are performed to obtain the difluorophosphate.

[0026] The by-product of the preparation of alkyl sulfonyl chloride in the present invention is dichlorophosphate, which can be used for the preparation of difluorophosphate. The dichlorophosphate can be directly fluorinated to obtain difluorophosphate. The process conditions are simple, the side reactions are few, different types of difluorophosphates with high purity can be prepared, the co-production of alkyl sulfonyl chloride and difluorophosphate is achieved, and the preparation cost is reduced.

[0027] Preferably, the molar ratio of the dichlorophosphate to the fluorinating agent is 1:(1-5), for example, 1:1, 1:2, 1:3, 1:4 or 1:5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the water content in the fluorination agent is ≤1000 ppm, for example, it can be 1000 ppm, 800 ppm, 500 ppm, 300 ppm or 100 ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the moisture content in the second solvent is 10-50 ppm, for example, 10 ppm, 20 ppm, 30 ppm, 40 ppm or 50 ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the second solvent comprises any one of nitriles, ketones, amides, sulfoxides, sulfones, ethers, carbonates or carboxylates, or a combination of at least two thereof.

[0031] Preferably, in the second solvent, nitriles include acetonitrile; ketones include any one of acetone, methyl ethyl ketone, cyclobutanone, 2,3-butanedione or acetylacetone or a combination of at least two thereof; amide solvents include any one of N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone or a combination of at least two thereof; sulfoxides include dimethyl sulfoxide; sulfones include dimethyl sulfone and / or cyclopentane sulfone; carbonates include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate or propylene carbonate. The invention relates to olefin esters, wherein the olefin esters include any one of ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, γ-valerolactone or γ-butyrolactone or a combination of at least two thereof; the ethers include any one of ethyl ether, isopropyl ether, methyl tert-butyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, anisole or phenethyl ether or a combination of at least two thereof.

[0032] Preferably, the fluorination agent includes any one of anhydrous hydrogen fluoride, lithium fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, sodium bifluoride, triethylamine hydrogen fluoride, pyridine hydrogen fluoride, potassium bifluoride or ammonium bifluoride, or a combination of at least two thereof.

[0033] Preferably, the post-treatment of the fluorination reaction includes: filtration, reduced pressure distillation and crystallization.

[0034] Preferably, a catalyst is added during the mixing of the fluorination reaction.

[0035] Preferably, the molar ratio of the catalyst to the dichlorophosphate is (0.005-0.06):1, for example, it can be 0.005:1, 0.01:1, 0.03:1, 0.05:1 or 0.06:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the moisture content in the catalyst is 10-100 ppm, for example, 10 ppm, 50 ppm or 100 ppm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, the catalyst comprises a crown ether compound, preferably any one of 18-crown-6, 15-crown-5, 12-crown-4, dibenzo-18-crown-6, benzo-18-crown-6-ether, dicyclohexane-18-crown-6, benzo-15-crown-5, dibenzo-15-crown-5 or benzo-12-crown-4, or a combination of at least two thereof.

[0038] The present invention also adds a catalyst during fluorination, and the addition of the catalyst accelerates the reaction rate, shortens the reaction time, and improves the yield. The catalyst used in the present invention is a crown ether catalyst, which can react with Li + 、Na + , K + The complex is formed, and therefore, in the fluorination reaction, the solubility of the hydrocarbon sulfonate or the fluorination agent in the second solvent can be increased to accelerate the fluorination reaction.

[0039] The fluorination reaction and post-treatment of the present invention are carried out in an environment with as little moisture as possible, wherein the moisture content of the fluorination reagent is controlled at ≤1000 ppm, and the moisture content of the catalyst is controlled at below 100 ppm, thereby further avoiding the generation of monochlorophosphate, phosphate and monofluorophosphate impurities.

[0040] As a preferred technical solution of the present invention, the method comprises the following steps:

[0041] (1) mixing an alkyl sulfonate with phosphorus oxychloride, performing a chlorination reaction, and extracting with a first solvent, filtering, and performing reduced pressure distillation to obtain the alkyl sulfonyl chloride;

[0042] wherein the molar ratio of the alkyl sulfonate to the phosphorus oxychloride is 1:(1-5);

[0043] (2) mixing a fluorination agent, a second solvent, a catalyst and the dichlorophosphate described in step (1), performing a fluorination reaction, filtering, distilling under reduced pressure and crystallizing to obtain the difluorophosphate;

[0044] Wherein, the molar ratio of the catalyst to the dichlorophosphate is (0.005-0.06):1, and the molar ratio of the dichlorophosphate to the fluorination agent is 1:(1-5);

[0045] The moisture content of the catalyst is 10-100 ppm, the moisture content of the fluorination agent is ≤1000 ppm, and the moisture content of the second solvent is 10-50 ppm.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The invention realizes the joint preparation of alkyl sulfonyl chloride and difluorophosphate, realizes efficient atomic utilization, and the method has simple process, is environmentally friendly, can be industrialized for production, and reduces the production costs of alkyl sulfonyl chloride and difluorophosphate; specifically, no solvent is used in the preparation of alkyl sulfonyl chloride, the direct contact reaction of raw materials strengthens the reaction effect, and possible solvent side reactions are avoided, and the by-products prepared by the alkyl sulfonyl chloride can be used for the preparation of difluorophosphate, which not only maximizes the utilization of atoms, but also simplifies the preparation process of difluorophosphate and reduces side reactions. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0049] The raw materials or reagents used in the present invention are all purchased from mainstream manufacturers in the market. Those without indicating the manufacturer or concentration are all analytically pure raw materials or reagents that can be routinely obtained. As long as they can play the expected role, there are no special restrictions. Raw materials with requirements for moisture need to be further dehydrated.

[0050] Calculation method of alkylsulfonyl chloride yield:

[0051] Calculation method of difluorophosphate yield:

[0052] If no specific technology or conditions are specified in the embodiments of the present invention, the technology or conditions described in the literature in the field or the product manual shall be followed.

[0053] Example 1

[0054] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, the method comprising the following steps:

[0055] (1) Chlorination reaction: 465.9 g (3.0 mol) of phosphorus oxychloride was added to a 1 L three-necked flask with stirring, and 128.1 g (1.0 mol) of lithium allyl sulfonate solid was added in batches over 30 minutes. After the addition was completed, the reaction solution was heated to 80° C. and reacted at normal pressure for 12 hours. The reaction solution was filtered and the anion chromatogram was taken to show that the lithium allyl sulfonate had been completely converted.

[0056] The chlorinated reaction solution was then cooled to 25°C, 400g of dichloromethane was added, stirred, washed and filtered, and the filter cake obtained by filtration was dried to obtain 140.8g of lithium dichlorophosphate, which was used as a raw material for fluorination reaction; the filtrate obtained was filtered, and dichloromethane was evaporated under reduced pressure to distill out 115.5g of allylsulfonyl chloride product;

[0057] The results of the NMR test of allylsulfonyl chloride are:

[0058] 1H-NMR (600MHz, CDCl3): δ6.05, δ5.67, δ4.27;

[0059] (2) Fluorination reaction: 140.8 g (1.0 mol) of lithium dichlorophosphate obtained in step (1) was added to a dry 1 L three-necked flask with stirring, 450 g of acetonitrile (water content of 20 ppm) was added and stirred to dissolve, and then 26.2 g of lithium fluoride (1.01 mol, water content of 200 ppm) and 1.76 g of 12-crown ether-4 catalyst (0.01 mol, water content of 100 ppm) were added, and the reaction was carried out at 25° C. for 8 h; the reaction solution was filtered, and the acetonitrile was evaporated under reduced pressure to obtain a colorless viscous liquid, 700 g of dimethyl carbonate (water content of 50 ppm) was added until white crystals precipitated, and 97.2 g of solid powder was obtained after filtration and drying. The anion chromatography detection was consistent with the standard sample PO2F2 - The peaks were consistent and identified as LiPO2F2 by NMR;

[0060] The results of NMR are:

[0061] 19F-NMR (600MHz, DMSO-d6): δ-79.56, δ-81.22;

[0062] 31P-NMR (600MHz, DMSO-d6): δ-11.94, δ-17.75, δ-23.56.

[0063] Example 2

[0064] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, the method comprising the following steps:

[0065] (1) Chlorination reaction: add 621.2 g (4.0 mol) of phosphorus oxychloride into a 1 L three-necked flask with stirring, add 144.1 g (1.0 mol) of sodium allyl sulfonate solid in batches over 30 minutes, and after the addition is completed, heat the reaction solution to 120° C. and react at normal pressure for 6 hours; take the reaction solution filter residue and detect the anion chromatogram, the sodium allyl sulfonate has been completely converted;

[0066] The chlorinated reaction solution was then cooled to 25°C, 600g of dichloromethane was added, stirred, washed and filtered, and the filter cake obtained by filtration was dried to obtain 156.9g of sodium dichlorophosphate, which was used as a raw material for fluorination reaction. The filtrate obtained was filtered, and dichloromethane was evaporated under reduced pressure to distill out 118.1g of allylsulfonyl chloride product;

[0067] The results of the NMR test of allylsulfonyl chloride are:

[0068] 1H-NMR (600MHz, CDCl3): δ6.05, δ5.67, δ4.27;

[0069] (2) Fluorination reaction: 156.9 g (1.0 mol) of sodium dichlorophosphate obtained in step (1) was added to a dry 2L three-necked flask with stirring, 1500 g of ethylene glycol dimethyl ether (water content of 25 ppm) was added and stirred to dissolve, and then 46.19 g of sodium fluoride (1.1 mol, water content of 300 ppm) and 2.2 g (0.01 mol) of 15-crown ether-5 catalyst (water content of 25 ppm) were added, and the mixture was reacted at 50° C. for 24 h; the reaction solution was filtered, and the ethylene glycol dimethyl ether was evaporated under reduced pressure to obtain a colorless viscous liquid, 700 g of dimethyl carbonate (water content of 50 ppm) was added until white crystals precipitated, and the solid powder of 108.3 g was obtained by filtration and drying. The peak of the solid powder was consistent with that of the standard sample PO2F2- by anion chromatography, and the solid powder was identified as NaPO2F2 by nuclear magnetic resonance;

[0070] The results of NMR are:

[0071] 19F-NMR (600MHz, DMSO-d6): δ-79.56, δ-81.22;

[0072] 31P-NMR (600MHz, DMSO-d6): δ-11.94, δ-17.75, δ-23.56.

[0073] Example 3

[0074] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, the method comprising the following steps:

[0075] (1) Chlorination reaction: Add 766.6 g (5.0 mol) of phosphorus oxychloride into a 1 L three-necked flask with stirring, and add 160.2 g (1.0 mol) of potassium allyl sulfonate solid in batches over 30 minutes. After the addition is completed, the reaction solution is heated to 100° C. and reacted at normal pressure for 8 hours; the reaction solution filtrate is taken and tested by anion chromatography, and the potassium allyl sulfonate has been completely converted;

[0076] The reaction solution after chlorination was then cooled to 25°C, 600g of dichloromethane was added, stirred, washed and filtered, and the filter cake obtained by filtration was dried to obtain 173.0g of potassium dichlorophosphate, which was used as a raw material for fluorination reaction; the filtrate obtained was filtered, and dichloromethane was evaporated under reduced pressure to distill out 116.7g of allylsulfonyl chloride product;

[0077] The results of the NMR test of allylsulfonyl chloride are:

[0078] 1H-NMR (600MHz, CDCl3): δ6.05, δ5.67, δ4.27;

[0079] (2) Fluorination reaction: 173.0 g (1.0 mol) of potassium dichlorophosphate obtained in step (1) was added to a dry 2L three-necked flask with stirring, 1000 g of N-methylpyrrolidone (water content of 30 ppm) was added and stirred to dissolve, and then 116.2 g of potassium fluoride (2.0 mol, water content of 200 ppm) and 15.86 g (0.06 mol) of 18-crown ether-6 catalyst (water content of 50 ppm) were added, and the mixture was reacted at 60° C. for 24 h; the reaction solution was filtered, and N-methylpyrrolidone was evaporated under reduced pressure to obtain a colorless viscous liquid, 700 g of dichloromethane (water content of 50 ppm) was added until white crystals precipitated, and the mixture was filtered and dried for 6 h to obtain 119.6 g of solid powder, which was consistent with the peak of the standard sample PO2F2- detected by anion chromatography, and was identified as KPO2F2 by nuclear magnetic resonance;

[0080] The results of NMR are:

[0081] 19F-NMR (600MHz, DMSO-d6): δ-79.56, δ-81.22;

[0082] 31P-NMR (600MHz, DMSO-d6): δ-11.94, δ-17.75, δ-23.56.

[0083] Example 4

[0084] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, the method comprising the following steps:

[0085] (1) Chlorination reaction: 154.8 g (1.01 mol) of phosphorus oxychloride was added to a 1 L three-necked flask with stirring, and 139.2 g (1.0 mol) of allyl ammonium sulfonate solid was added in batches over 30 minutes. After the addition was completed, the reaction solution was heated to 25° C. and reacted at normal pressure for 24 hours. The reaction solution was filtered and the anion chromatogram was taken to show that the allyl ammonium sulfonate had been completely converted.

[0086] Then the reaction liquid after chlorination was cooled to 25°C, 600g of n-hexane was added, stirred, washed and filtered, and the filter cake obtained by filtration was dried to obtain 151.9.0g of ammonium dichlorophosphate, which was used as a raw material for fluorination reaction. The filtrate obtained was filtered, and n-hexane was evaporated under reduced pressure to distill out 123.8g of allyl sulfonyl chloride product;

[0087] The results of the NMR test of allylsulfonyl chloride are:

[0088] 1H-NMR (600MHz, CDCl3): δ6.05, δ5.67, δ4.27;

[0089] (2) Fluorination reaction: 151.9 g (1.0 mol) of ammonium dichlorophosphate obtained in step (1) was added to a dry 2L three-necked flask with stirring, 1000 g of ethylene glycol dimethyl ether (water content 25 ppm) was added and stirred to dissolve, and then 37.0 g of ammonium fluoride (1.0 mol, water content 450 ppm) and 1.32 g (0.005 mol) of 18-crown ether-6 catalyst (water content 10 ppm) were added, and the mixture was reacted at 25° C. for 8 h; the reaction solution was filtered, and the filtrate was evaporated under reduced pressure to remove ethylene glycol dimethyl ether to obtain a colorless viscous liquid, 700 g of ether (water content 10 ppm) was added until white crystals precipitated, and the solid powder of 109.5 g was obtained by filtering and drying. The anion chromatography detection was consistent with the peak of the standard sample PO2F2-, and the NMR identification was NH4PO2F2;

[0090] The results of NMR are:

[0091] 19F-NMR (600MHz, DMSO-d6): δ-79.56, δ-81.22;

[0092] 31P-NMR (600MHz, DMSO-d6): δ-11.94, δ-17.75, δ-23.56.

[0093] Example 5

[0094] This embodiment provides a method for co-producing allyl sulfonyl chloride and difluorophosphate, which is the same as that of Embodiment 1 except that the molar ratio of lithium allyl sulfonate to phosphorus oxychloride in step (1) is 1:0.9.

[0095] Example 6

[0096] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate. The method is the same as that of Embodiment 1 except that the catalyst 12-crown ether-4 is not added in step (2).

[0097] Example 7

[0098] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, which is the same as that of embodiment 1 except that the 12-crown ether-4 catalyst in step (2) is replaced in equal moles by a phase transfer catalyst, tetramethylammonium chloride.

[0099] Example 8

[0100] This embodiment provides a method for co-producing allylsulfonyl chloride and difluorophosphate, which is the same as that of Embodiment 1 except that the water content in acetonitrile, catalyst, lithium fluoride and dimethyl carbonate in step (2) is 2000 ppm.

[0101] Comparative Example 1

[0102] This comparative example provides a method for preparing allylsulfonyl chloride, which is the same as Example 1 except that the phosphorus oxychloride in step (1) is replaced by thionyl chloride in equal moles and step (2) is not performed.

[0103] Comparative Example 2

[0104] This comparative example provides a method for preparing allyl sulfonyl chloride, which is the same as Example 1 except that during the chlorination in step (1), o-xylene solvent having a mass that is 5 times the mass of sodium allyl sulfonate is added.

[0105] The yields and gas chromatographic purities of the allyl sulfonyl chloride and difluorophosphate obtained in the above Examples 1-8 and Comparative Example 2, and the yields and anion chromatographic purity of the allyl sulfonyl chloride, and the yields and anion chromatographic purity of the difluorophosphate obtained in Comparative Example 1 are shown in Table 1:

[0106] Table 1

[0107]

[0108] From the above table we can see that:

[0109] (1) The method of the present invention can co-produce alkyl sulfonyl chloride and difluorophosphate, and the yield and purity of the co-produced products are both high, wherein the yield of alkyl sulfonyl chloride can reach more than 80%, and the purity can reach more than 99%, and the yield of difluorophosphate can reach more than 85%, and the purity can reach more than 99.5%; it can be seen from Examples 1 and 5 that the molar amount of phosphorus oxychloride is preferably greater than or equal to that of allyl sulfonate, thereby further promoting the dispersion and conversion of allyl sulfonate; it can be seen from Examples 1 and 6-7 that the addition of a specific catalyst during fluorination in the present invention can further improve the yield and purity of difluorophosphate; it can be seen from Examples 1 and 8 that the reaction under conditions of low moisture content can avoid the generation of by-products, thereby improving the yield and purity of difluorophosphate.

[0110] (2) As can be seen from Example 1 and Comparative Example 1, the present invention uses phosphorus oxychloride to chlorinate alkyl sulfonates. Compared with the use of thionyl chloride, no toxic and harmful gases such as sulfur dioxide are generated, and valuable by-products can be generated as raw materials for preparing difluorophosphates. At the same time, the obtained product has high yield and purity. As can be seen from Example 1 and Comparative Example 2, the present invention does not need to add a solvent for the chlorination of alkyl sulfonyl chloride, and the raw materials are directly contacted for reaction, which not only enhances the reaction effect, but also avoids possible solvent side reactions, further improving the purity and yield of the product.

[0111] In summary, the present invention provides a method for preparing an alkyl sulfonyl chloride, and a method for co-producing an alkyl sulfonyl chloride and a difluorophosphate. In particular, the method can simultaneously prepare an alkyl sulfonyl chloride and a difluorophosphate, thereby maximizing the atomic utilization rate, and the process is simple and can be industrially produced on a large scale, thereby greatly reducing the production costs of the alkyl sulfonyl chloride and the difluorophosphate.

[0112] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an alkyl sulfonyl chloride, characterized in that: The preparation method comprises the following steps: The alkyl sulfonate is mixed with phosphorus oxychloride, subjected to chlorination reaction and post-treatment, to obtain the alkyl sulfonyl chloride.

2. The preparation method according to claim 1, characterized in that: The molar ratio of the alkyl sulfonate to phosphorus oxychloride is 1:(1-5); Preferably, the alkyl sulfonyl chloride comprises allyl sulfonyl chloride.

3. The preparation method according to claim 1 or 2, characterized in that: The post-treatment of the chlorination reaction includes: extracting with a first solvent, filtering and distilling under reduced pressure to obtain the alkyl sulfonyl chloride; Preferably, the first solvent includes any one of chain alkanes, cycloalkanes, halogenated alkanes, aromatic hydrocarbons, halogenated aromatic hydrocarbons, carbonates, carboxylates or ether compounds, or a combination of at least two thereof.

4. The preparation method according to any one of claims 1 to 3, characterized in that The hydrocarbyl sulfonate includes any one of hydrocarbyl sulfonate lithium, hydrocarbyl sulfonate sodium, hydrocarbyl sulfonate potassium or hydrocarbyl sulfonate ammonium, or a combination of at least two thereof.

5. A method for co-producing alkyl sulfonyl chloride and difluorophosphate, characterized in that: The method comprises the following steps: Prepared by the preparation method according to any one of claims 1 to 4 to obtain alkyl sulfonyl chloride and dichlorophosphate; A fluorination agent, a second solvent and the dichlorophosphate are mixed, and a fluorination reaction and post-treatment are performed to obtain the difluorophosphate.

6. The method according to claim 5, characterized in that The molar ratio of the dichlorophosphate to the fluorination agent is 1:(1-5); Preferably, the water content in the fluorination agent is ≤1000 ppm.

7. The method according to claim 5 or 6, characterized in that: The moisture content of the second solvent is 10-50 ppm; Preferably, the second solvent comprises any one of nitriles, ketones, amides, sulfoxides, sulfones, ethers, carbonates or carboxylates, or a combination of at least two thereof.

8. The method according to any one of claims 5 to 7, characterized in that: The fluorination agent includes any one or a combination of at least two of anhydrous hydrogen fluoride, lithium fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, sodium bifluoride, triethylamine hydrogen fluoride, pyridine hydrogen fluoride, potassium bifluoride or ammonium bifluoride; Preferably, the post-treatment of the fluorination reaction includes: filtration, reduced pressure distillation and crystallization.

9. The method according to any one of claims 5 to 8, characterized in that: A catalyst is also added during the mixing of the fluorination reaction; Preferably, the molar ratio of the catalyst to the dichlorophosphate is (0.005-0.06):1; Preferably, the moisture content in the catalyst is 10-100 ppm; Preferably, the catalyst comprises a crown ether compound, preferably any one of 18-crown-6, 15-crown-5, 12-crown-4, dibenzo-18-crown-6, benzo-18-crown-6-ether, dicyclohexane-18-crown-6, benzo-15-crown-5, dibenzo-15-crown-5 or benzo-12-crown-4, or a combination of at least two thereof.

10. The method according to any one of claims 5 to 9, characterized in that: The method comprises the following steps: (1) mixing an alkyl sulfonate with phosphorus oxychloride, performing a chlorination reaction, and extracting with a first solvent, filtering, and performing reduced pressure distillation to obtain the alkyl sulfonyl chloride; wherein the molar ratio of the alkyl sulfonate to the phosphorus oxychloride is 1:(1-5); (2) mixing a fluorination agent, a second solvent, a catalyst and the dichlorophosphate described in step (1), performing a fluorination reaction, filtering, distilling under reduced pressure and crystallizing to obtain the difluorophosphate; Wherein, the molar ratio of the catalyst to the dichlorophosphate is (0.005-0.06):1, and the molar ratio of the dichlorophosphate to the fluorination agent is 1:(1-5); The moisture content of the catalyst is 10-100 ppm, the moisture content of the fluorination agent is ≤1000 ppm, and the moisture content of the second solvent is 10-50 ppm.

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