Preparation method of anhydrous N, N-dimethyl amino sulfonyl fluoride

Abstract

The invention relates to the technical field of chemical synthesis, and discloses a preparation method of anhydrous N, N-dimethyl amino sulfuryl fluoride, which comprises the following steps: (1) introducing sulfuryl fluoride gas into a dimethylamine organic solution to carry out nucleophilic substitution reaction, and then adding triethylamine to obtain a mixed solution containing N, N-dimethyl amino sulfuryl fluoride; and (2) sequentially carrying out normal-pressure rectification and reduced-pressure rectification on the mixed solution containing the N, N-dimethyl amino sulfonyl fluoride to obtain the N, N-dimethyl amino sulfonyl fluoride. According to the method, water is not introduced in the whole process, the risk of water residue is avoided, and the prepared product is high in yield and purity.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, and in particular to a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride. Background Technology

[0002] N,N-Dimethylaminosulfonyl fluoride (FSO2NMe2), with its unique fluorinated sulfonamide molecular structure, exhibits excellent electrochemical stability and interface regulation capabilities. As a core solvent or additive for lithium battery electrolytes, it can significantly improve the cycle stability and electrochemical performance of lithium battery systems.

[0003] Currently, the synthetic route for preparing N,N-dimethylaminosulfonyl fluoride is mostly based on secondary amines and sulfuryl fluoride. For example, Chinese patent application CN109563031A discloses a method for preparing N-(fluorosulfonyl)dimethylamine. This method uses dimethylamine and sulfuryl fluoride as reaction substrates, reacting them in an aqueous system or an organic solvent to generate the target product. The byproducts are then removed by water washing and phase separation to finally obtain N,N-dimethylaminosulfonyl fluoride. However, the water washing method in the above method easily leads to trace amounts of residual moisture in the product. Lithium-ion battery electrolytes have extremely stringent requirements for moisture content (usually below 10 ppm). Trace amounts of moisture can cause electrolyte decomposition and electrode corrosion, seriously affecting the battery's electrochemical performance and safety stability, thus hindering the direct application of the product in the lithium-ion battery field. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride. This method does not introduce water throughout the entire process, thus avoiding the risk of residual moisture, and the resulting product has high yield and purity.

[0005] The specific technical solution of this invention is: a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: (1) Passing sulfur fluoride gas into a dimethylamine organic solution to carry out a nucleophilic substitution reaction, and then adding triethylamine to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride; (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation and vacuum distillation in sequence to obtain N,N-dimethylaminosulfonyl fluoride.

[0006] In the above preparation method, dimethylamine and thiosulfonyl fluoride undergo a nucleophilic substitution reaction in an anhydrous system to generate the target product N,N-dimethylaminosulfonyl fluoride and hydrogen fluoride (HF) byproduct. No additional hydrolysis side reactions occur, laying a low-impurity foundation for subsequent purification. Triethylamine is added to the solution after the reaction of dimethylamine and thiosulfonyl fluoride to fix the generated hydrogen fluoride. The resulting triethylamine hydrofluorate is highly stable and insoluble in the target product. During the atmospheric distillation stage, the organic solvent and dimethylamine are azeotropically distilled out. During the vacuum distillation stage, N,N-dimethylaminosulfonyl fluoride is vaporized and distilled out. The triethylamine hydrofluorate is non-volatile and ultimately remains at the bottom of the column, achieving complete separation from the target product. This method, by anhydrousizing the raw material system, the reaction process, and the post-treatment stages, avoids the risk of residual moisture by preventing the introduction of water throughout the entire process. Simultaneously, the hydrogen fluoride byproduct is fixed by triethylamine, allowing the reaction solution to be directly distilled to obtain high-purity N,N-dimethylaminosulfonyl fluoride.

[0007] Optionally, in step (1), the concentration of the dimethylamine organic solution is 20wt%~40wt%, preferably 25wt%~35wt%.

[0008] Optionally, in step (1), the molar ratio of dimethylamine solute to thioyl fluoride in the dimethylamine organic solution is 2:1 to 2.1:1.

[0009] In the above technical solution, dimethylamine is added in a slight excess. The excess dimethylamine can immediately combine with the generated HF to form dimethylamine hydrofluoric acid salt. This not only avoids the direct interaction of free HF with the SN bond of the target product, which would lead to the decomposition of the target product, but also inhibits the volatilization of HF and prevents corrosion of equipment. Subsequently added triethylamine undergoes a displacement reaction with the dimethylamine hydrofluoric acid salt, which not only releases recyclable dimethylamine, but also converts HF into a more stable triethylamine hydrofluoric acid salt that is insoluble in the target product.

[0010] Optionally, in step (1), the organic solvent in the dimethylamine organic solution is selected from one or more of acetonitrile, methyl ether, diethyl ether, tetrahydrofuran, and benzene.

[0011] Optionally, in step (1), the molar ratio of triethylamine to dimethylamine solute in the dimethylamine organic solution is 1:6 to 1.1:6, preferably 1.02:6 to 1.05:6.

[0012] In the above technical solution, a slight excess of triethylamine can ensure that HF ​​is completely fixed.

[0013] Optionally, in step (1), the reaction temperature of the nucleophilic substitution reaction is 0~15℃, preferably 4~8℃.

[0014] In the above technical solution, low temperature conditions can inhibit the volatilization of sulfuryl fluoride and the decomposition of dimethylamine, while reducing the corrosiveness of HF and ensuring the stable progress of the reaction.

[0015] Optionally, in step (1), after adding triethylamine, the mixture is stirred for 20 min to 1 h to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. Preferably, the stirring time is 30 min to 40 min.

[0016] Optionally, in step (2), the pressure of the vacuum distillation is 2~8 kPa, preferably 5~7 kPa.

[0017] In the above technical solution, the reduced pressure condition can significantly lower the boiling point of the target product and avoid product decomposition caused by high temperature (such as the breakage of the -SO2F group); at the same time, the triethylamine hydrofluorate remains at the bottom of the distillation column, and the target product is condensed and collected in the form of vapor, finally obtaining high-purity N,N-dimethylaminosulfonyl fluoride.

[0018] Optionally, in step (2), dimethylamine organic solution is separated by atmospheric distillation and recovered as a starting material to be recycled in step (1).

[0019] In the above technical solution, the purpose of atmospheric distillation is to separate most of the solvent and the displaced dimethylamine in the mixed solution. During this process, the target product triethylamine hydrofluoric acid will not be distilled out. The dimethylamine and the solvent form a dimethylamine organic solution, which can be directly used as the starting material for recycling in step (1) without additional purification, thereby realizing the resource utilization of raw materials and reducing costs.

[0020] Compared with the prior art, the present invention has at least the following advantages: (1) This method avoids the risk of residual moisture by anhydrous raw material system, anhydrous reaction process and anhydrous post-treatment process, without introducing water throughout the process. At the same time, the hydrogen fluoride byproduct is fixed by triethylamine, so that the reaction liquid can be directly distilled to obtain high-purity N,N-dimethylaminosulfonyl fluoride. (2) The solvent and the displaced dimethylamine are collected by atmospheric distillation. The recovered dimethylamine organic solution can be directly used as a starting material for recycling without additional purification, thereby realizing the resource utilization of raw materials and reducing costs. Detailed Implementation

[0021] The present invention will now be described through specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in the present invention, and the scope of protection of the present invention is defined by the appended claims and any equivalents thereof.

[0022] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Unless otherwise specified, the raw materials and equipment used in this invention are conventional in the art and can be obtained through conventional commercial means; unless otherwise specified, the methods used in this invention are conventional methods in the art.

[0023] In this invention, atmospheric distillation refers to distillation performed under natural atmospheric pressure without artificial pressurization or depressurization.

[0024] Example 1: This invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: (1) 40.86 g of dimethylamine gas was passed into 120.5 g of acetonitrile solution to prepare a 25.32 wt% dimethylamine acetonitrile solution. At 4 °C, 45.32 g of sulfuryl fluoride gas was passed into the dimethylamine acetonitrile solution to carry out a nucleophilic substitution reaction. After the gas was passed, 15.28 g of triethylamine was added and stirred for 30 min to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation. The temperature at the top of the distillation column was stabilized at 82℃±2℃ and the distillate flow rate decreased significantly, which indicated the separation endpoint. At this point, atmospheric distillation was stopped and 107.07g of distillate solution was collected. Subsequently, the remaining mixed solution in the distillation column was subjected to vacuum distillation to reduce the system pressure to 5kPa. The target product N,N-dimethylaminosulfonyl fluoride was vaporized by heating. The vapor was collected after condensation. When the mass of the collected target product no longer increased, vacuum distillation was stopped, and 53.28g of N,N-dimethylaminosulfonyl fluoride was finally obtained.

[0025] Gas chromatography analysis and calculations showed that the yield of N,N-dimethylaminosulfonyl fluoride was 94.38% and the purity was 99.92%.

[0026] The prepared N,N-dimethylaminosulfonyl fluoride was then subjected to specific impurity detection using inductively coupled plasma atomic emission spectrometry (ICP), chemical titration, and colorimetry. The results showed that the HF content was 20.71 ppm and the Cl content was 20.71 ppm. - : 1.74ppm; Na: 4.21ppm; K: 2.63ppm; Ca: 0.51ppm; Ni: ND; Fe: 0.11ppm; Pb: 0.34ppm; Color number: 10APHA.

[0027] Testing standards: HF: ≤50ppm; Cl -Color: ≤10ppm; Color number: ≤50APHA; K / Ca / Pb ≤5ppm; Na ≤10ppm; Fe ≤2ppm; Ni ≤1ppm. Comparing the above test results with the test standards, it can be seen that the N,N-dimethylaminosulfonyl fluoride prepared in this example meets the standard requirements, and most indicators are significantly better than the limits.

[0028] The distillate solution from atmospheric distillation was analyzed, and the mass fraction of dimethylamine was 17.62 wt%. The remaining main component was acetonitrile, the organic solvent used in the reaction. Therefore, the distillate solution was a dimethylamine organic solution.

[0029] Example 2: This invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: (1) 81.59 g of dimethylamine gas was passed into 161.72 g of dimethyl ether solution to prepare a 33.53 wt% dimethylamine dimethyl ether solution. At 10 °C, 90.97 g of thiosulfonyl fluoride gas was passed into the dimethylamine dimethyl ether solution to carry out a nucleophilic substitution reaction. After the gas was passed, 30.37 g of triethylamine was added and stirred for 40 min to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation. When the temperature at the top of the distillation column stabilized at 82℃±2℃ and the distillate flow rate decreased significantly, the separation endpoint was reached. At this point, atmospheric distillation was stopped and 152.82g of distillate solution was collected. Subsequently, the remaining mixed solution in the distillation column was subjected to vacuum distillation to reduce the system pressure to 7kPa. The target product N,N-dimethylaminosulfonyl fluoride was vaporized by heating. The vapor was collected after condensation. When the mass of the target product collected by condensation no longer increased, vacuum distillation was stopped, and 106.04g of N,N-dimethylaminosulfonyl fluoride was finally obtained.

[0030] Gas chromatography analysis and calculations showed that the yield of N,N-dimethylaminosulfonyl fluoride was 93.57% and the purity was 99.95%.

[0031] The prepared N,N-dimethylaminosulfonyl fluoride was then subjected to specific impurity detection using inductively coupled plasma atomic emission spectrometry (ICP), chemical titration, and colorimetry. The results showed that the HF content was 28.42 ppm and the Cl content was 28.42 ppm. - 0.84ppm; Na: 3.61ppm; K: 2.54ppm; Ca: 0.21ppm; Ni: ND; Fe: ND; Pb: 0.83ppm; Color code: 10APHA. Comparing the above test results with the testing standards, it can be seen that the N,N-dimethylaminosulfonyl fluoride prepared in this embodiment meets the standard requirements, and most indicators are significantly better than the limits.

[0032] The distillate solution from atmospheric distillation was analyzed, revealing that the mass fraction of dimethylamine was 24.30 wt%, with the remaining main component being dimethyl ether, the organic solvent used in the reaction. This distillate solution was a dimethylamine organic solution, which was recovered and recycled back to step (1) as a starting material. This distillate solution, along with the newly added dimethylamine gas and dimethyl ether solution from step (1), was prepared into a dimethylamine dimethyl ether solution of approximately 30 wt%, which underwent a nucleophilic substitution reaction with thioyl fluoride.

[0033] Example 3: This invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: (1) 42.85g of dimethylamine gas was passed into 145.88g of diethyl ether solution to prepare a 22.70wt% dimethylamine diethyl ether solution. At 15℃, 47.32g of thiosulfonyl fluoride gas was passed into the dimethylamine diethyl ether solution to carry out a nucleophilic substitution reaction. After the gas was passed, 16.42g of triethylamine was added and stirred for 20min to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation. When the temperature at the top of the distillation column stabilized at 82℃±2℃ and the distillate flow rate decreased significantly, the separation endpoint was reached. At this point, atmospheric distillation was stopped and 126.25g of distillate solution was collected. Subsequently, the remaining mixed solution in the distillation column was subjected to vacuum distillation to reduce the system pressure to 7.5 kPa. The target product N,N-dimethylaminosulfonyl fluoride was vaporized by heating. The vapor was collected after condensation. When the mass of the target product collected by condensation no longer increased, vacuum distillation was stopped, and 50.82g of N,N-dimethylaminosulfonyl fluoride was finally obtained.

[0034] Gas chromatography analysis and calculations showed that the yield of N,N-dimethylaminosulfonyl fluoride was 86.21% and the purity was 99.97%.

[0035] The prepared N,N-dimethylaminosulfonyl fluoride was then subjected to specific impurity detection using inductively coupled plasma atomic emission spectrometry (ICP), chemical titration, and colorimetry. The results showed that the HF content was 19.55 ppm and the Cl content was 19.55 ppm. - 0.98ppm; Na: 4.54ppm; K: 0.92ppm; Ca: 0.18ppm; Ni: ND; Fe: 0.20ppm; Pb: 1.31ppm; Color code: 5APHA. Comparing the above test results with the testing standards, it can be seen that the N,N-dimethylaminosulfonyl fluoride prepared in this embodiment meets the standard requirements, and most indicators are significantly better than the limits.

[0036] The distillate solution from atmospheric distillation was tested and found to contain 14.93 wt% dimethylamine, with the remaining main component being diethyl ether, the organic solvent used in the reaction. Therefore, the distillate solution was a dimethylamine organic solution.

[0037] Example 4: Based on Example 1, the present invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: 10.68 g of dimethylamine gas was passed through the dimethylamine acetonitrile solution distilled at atmospheric pressure in Example 1 to prepare a 33.49 wt% dimethylamine acetonitrile solution. Then, 33.09 g of thiosulfonyl fluoride gas was passed through at 4 °C to carry out a nucleophilic substitution reaction. After the gas passage was completed, 11.31 g of triethylamine was added and stirred for 30 min to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation. The temperature at the top of the distillation column was stabilized at 82℃±2℃ and the distillate flow rate decreased significantly, which means the separation endpoint was reached. At this time, atmospheric distillation was stopped and 75.96g of distillate solution was collected. Then, the remaining mixed solution in the distillation column was subjected to vacuum distillation to reduce the system pressure to 5kPa. The target product N,N-dimethylaminosulfonyl fluoride was vaporized by heating. The vapor was collected after condensation. When the mass of the target product collected by condensation no longer increased, vacuum distillation was stopped, and 38.19g of N,N-dimethylaminosulfonyl fluoride was finally obtained.

[0038] The distillate solution from atmospheric distillation was analyzed, and the mass fraction of dimethylamine was 17.71 wt%. The remaining main component was acetonitrile, the organic solvent used in the reaction. Therefore, the distillate solution was a dimethylamine organic solution.

[0039] Gas chromatography analysis and calculations showed that the yield of N,N-dimethylaminosulfonyl fluoride was 92.66% and the purity was 99.98%.

[0040] The prepared N,N-dimethylaminosulfonyl fluoride was then subjected to specific impurity detection using inductively coupled plasma atomic emission spectrometry (ICP), chemical titration, and colorimetry. The results showed that the HF content was 8.1 ppm and the Cl content was 8.1 ppm. - 0.91ppm; Na: 2.17ppm; K: 0.32ppm; Ca: ND; Ni: ND; Fe: 0.12ppm; Pb: 0.66ppm; Color code: 5APHA. Comparing the above test results with the testing standards, it can be seen that the N,N-dimethylaminosulfonyl fluoride prepared in this embodiment meets the standard requirements, and most indicators are significantly better than the limits.

[0041] Example 5: Based on Example 2, the present invention provides a method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, comprising the following steps: The dimethylamine methyl ether solution distilled from the atmospheric distillation in Example 2 was subjected to a nucleophilic substitution reaction by passing 40.42 g of thiosulfonyl fluoride gas through it at 4°C. After the gas passage was completed, 13.68 g of triethylamine was added and the mixture was stirred for 30 min to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride. (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation. The temperature at the top of the distillation column was stabilized at 82℃±2℃ and the flow rate of the distillate decreased significantly, which means that the separation endpoint was reached. At this time, the atmospheric distillation was stopped and 104.42g of distillate solution was collected. Then, the remaining mixed solution in the distillation column was subjected to vacuum distillation to reduce the system pressure to 5kPa. The target product N,N-dimethylaminosulfonyl fluoride was vaporized by heating. The vapor was collected after condensation. When the mass of the target product collected by condensation no longer increased, the vacuum distillation was stopped and 47.9g of N,N-dimethylaminosulfonyl fluoride was finally obtained.

[0042] The distillate solution from atmospheric distillation was tested and found to contain 16.68 wt% dimethylamine, with the remaining main component being dimethyl ether, the organic solvent used in the reaction. Therefore, the distillate solution was a dimethylamine organic solution.

[0043] According to gas chromatography detection and calculation, the yield of N,N-dimethylaminosulfonyl fluoride was 95.12% and the purity was 99.95%.

[0044] The prepared N,N-dimethylaminosulfonyl fluoride was then subjected to specific impurity detection using inductively coupled plasma atomic emission spectrometry (ICP), chemical titration, and colorimetry. The results showed that the HF content was 8.1 ppm and the Cl content was 8.1 ppm. - 0.91ppm; Na: 2.17ppm; K: 0.32ppm; Ca: ND; Ni: ND; Fe: 0.12ppm; Pb: 0.66ppm; Color code: 5APHA. Comparing the above test results with the testing standards, it can be seen that the N,N-dimethylaminosulfonyl fluoride prepared in this embodiment meets the standard requirements, and most indicators are significantly better than the limits.

[0045] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride, characterized in that, Includes the following steps: (1) Passing sulfur fluoride gas into a dimethylamine organic solution to carry out a nucleophilic substitution reaction, and then adding triethylamine to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride; (2) The mixed solution containing N,N-dimethylaminosulfonyl fluoride was subjected to atmospheric distillation and vacuum distillation in sequence to obtain N,N-dimethylaminosulfonyl fluoride.

2. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), the concentration of the dimethylamine organic solution is 20wt%~40wt%.

3. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), the molar ratio of dimethylamine solute to thioyl fluoride in the dimethylamine organic solution is 2:1 to 2.1:

1.

4. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), the organic solvent in the dimethylamine organic solution is selected from one or more of acetonitrile, methyl ether, diethyl ether, tetrahydrofuran, and benzene.

5. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), the molar ratio of triethylamine to dimethylamine solute in the dimethylamine organic solution is 1:6 to 1.1:

6.

6. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), the reaction temperature of the nucleophilic substitution reaction is 0~15℃.

7. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (1), after adding triethylamine, the mixture is stirred for 20 min to 1 h to obtain a mixed solution containing N,N-dimethylaminosulfonyl fluoride.

8. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 1, characterized in that, In step (2), the pressure of the vacuum distillation is 2~8 kPa.

9. The method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to claim 8, characterized in that, The pressure of the vacuum distillation is 5~7 kPa.

10. A method for preparing anhydrous N,N-dimethylaminosulfonyl fluoride according to any one of claims 1 to 9, characterized in that, In step (2), dimethylamine organic solution is separated by atmospheric distillation and recovered as a starting material to be recycled in step (1).