Synthetic method of 4-fluoropropane disulfonic anhydride
The synthesis of 4-fluoromalonate anhydride through the reaction of 1,3-dichloro-2-fluoropropane with sodium sulfite and subsequent dehydration addresses the synthesis gap, enhancing battery performance.
Patent Information
- Application Number
- CN202510730625.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-03
- Publication Date
- 2025-07-15
AI Technical Summary
There is currently no patent report on the synthesis of 4-fluoromalondisulfonic anhydride, and the prior art cannot effectively synthesize the lithium-ion battery electrolyte additive with excellent flame retardant properties.
1,3-dichloro-2-fluoropropane and sodium sulfite are used as starting materials, and 4-fluoromadisulfonic anhydride is prepared through reflux reaction, dehydration reaction and recrystallization steps. The specific steps include reflux temperature 40-120°C, selection of dehydration agents and the use of recrystallization solvents.
The synthesis of 4-fluoromalondisulfonic anhydride has been achieved, providing beneficial ideas for its product development. The product yield and purity reach 75.08%-99.49%, meeting the needs of high-performance battery electrolyte additives.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of the synthesis of battery electrolyte additives, and relates to a synthesis method of 4-fluoropropanedisulfonic anhydride. Background Art
[0002] Propanedisulfonic anhydride is a new type of lithium-ion battery electrolyte additive. It can be used as an SEI film-forming additive to inhibit the initial capacity decline of the battery, increase the initial discharge capacity, reduce the battery swelling after high-temperature storage, and improve the charge-discharge performance and cycle times of the battery. Its modified product, 4-fluoropropanedisulfonic anhydride, has more excellent performance in flame retardancy, but there is no relevant synthesis patent report yet. Summary of the Invention
[0003] The purpose of the present invention is to provide a synthesis method of 4-fluoropropanedisulfonic anhydride.
[0004] The technical solution adopted by the present invention to achieve its purpose:
[0005] A synthesis method of 4-fluoropropanedisulfonic anhydride, comprising the following steps:
[0006] S1. Using 1,3-dichloro-2-fluoropropane (CAS: 816-38-6) and sodium sulfite as starting materials, carrying out a reflux reaction. After the reaction is completed, the solvent is removed to obtain a crude product of 2-fluoro-1,3-propanedisulfonic acid sodium salt, and the molecular structural formula is
[0007] S2. Adding a dehydrating agent to carry out a dehydration reaction to obtain a crude product of 4-fluoropropanedisulfonic anhydride;
[0008] S3. Through recrystallization, obtaining a finished product of 4-fluoropropanedisulfonic anhydride (CAS: 1234622-63-9), and the molecular structural formula is
[0009] Furthermore, the molar ratio of 1,3-dichloro-2-fluoropropane to sodium sulfite is 1:(2.3 - 3).
[0010] Furthermore, the solvent used in the reflux reaction is pure water, or a mixed solvent of pure water and one of ethanol, tetrahydrofuran, methanol, and acetone.
[0011] Furthermore, the temperature of the reflux reaction is 40 - 120 °C, and the time of the reflux reaction is 2 - 24 h.
[0012] Furthermore, the dehydrating agent is selected from one or any combination of thionyl chloride, phosphorus trichloride, phosphorus oxychloride, phosphorus pentoxide, sulfuryl chloride, and solid phosgene.
[0013] Further, no solvent is used in the dehydration reaction, or the selected solvent is one of dichloromethane, dichloroethane, tetrahydrofuran, acetonitrile, and ethyl acetate.
[0014] Further, the temperature of the dehydration reaction is 30 - 150 °C.
[0015] Further, the addition amount of the dehydrating agent is 1 - 20 times that of the crude product of 2 - fluoro - 1,3 - propanedisulfonic acid sodium salt.
[0016] Further, the solvent for recrystallization is one of dichloromethane, dichloroethane, acetonitrile, ethyl acetate, acetone, and tetrahydrofuran.
[0017] Further, 1,3 - dibromo - 2 - fluoropropane is used to replace 1,3 - dichloro - 2 - fluoropropane. When 1,3 - dibromo - 2 - fluoropropane is used to replace 1,3 - dichloro - 2 - fluoropropane, the reaction activity will increase, but the cost will increase; and 1,3 - dibromo - 2 - fluoropropane is not as easy to prepare as 1,3 - dichloro - 2 - fluoropropane.
[0018] The beneficial effects of the present invention are as follows:
[0019] The present invention provides a synthesis method of 4 - fluoropropanedisulfonic anhydride, filling the technical gap in the synthesis of 4 - fluoropropanedisulfonic anhydride and providing a beneficial idea for the product development of 4 - fluoropropanedisulfonic anhydride. Specific Embodiments
[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0021] The synthesis route of the present invention is as follows:
[0022]
[0023] Example 1
[0024] In a 500 ml reaction flask, 200 grams of pure water and 50 grams of ethanol are added; then 31.5 grams of sodium sulfite is added thereto and stirred until dissolved; then 13.1 grams of 1,3 - dichloro - 2 - fluoropropane is added, and the temperature is raised to 90 °C, and the reaction is refluxed for 12 h; vacuum is slowly introduced to remove the solvent, and a crude product of 2 - fluoro - 1,3 - propanedisulfonic acid sodium salt and unreacted sodium sulfite solid are obtained.
[0025] The solid was slowly added to 200 g of thionyl chloride, and the temperature was raised to 80 °C. The reaction was carried out for 4 h, and the unreacted thionyl chloride was removed under reduced pressure to obtain a crude product of 4-fluoropropanedisulfonic anhydride.
[0026] 200 ml of dichloroethane was added, and the temperature was raised to 60 °C. The mixture was filtered to remove the by-product sodium chloride. The filtrate was cooled to 0 - 5 °C and kept at this temperature for 1 h. Then, it was filtered by suction, and the filter cake was dried to obtain 15.33 g of the finished product of 4-fluoropropanedisulfonic anhydride, with a yield of 75.08% and a purity of 99.26%.
[0027] Example 2
[0028] In a 500 ml reaction flask, 160 g of pure water and 50 g of acetonitrile were added; 30.2 g of sodium sulfite was added and stirred until dissolved; then 10.5 g of 1,3-dichloro-2-fluoropropane was added, and the temperature was raised to 90 °C. The mixture was refluxed for 8 h; a vacuum was slowly introduced to remove the solvent, obtaining a crude product of sodium 2-fluoro-1,3-propanedisulfonate and unreacted solid sodium sulfite.
[0029] The solid was slowly added to 160 g of thionyl chloride, and the temperature was raised to 90 °C. The reaction was carried out for 4 h, and the unreacted thionyl chloride was removed under reduced pressure to obtain a crude product of 4-fluoropropanedisulfonic anhydride.
[0030] 200 ml of dichloroethane was added, and the temperature was raised to 60 °C. The mixture was filtered to remove the by-product sodium chloride. The filtrate was cooled to 0 - 5 °C and kept at this temperature for 1 h. Then, it was filtered by suction, and the filter cake was dried to obtain 12.36 g of the finished product of 4-fluoropropanedisulfonic anhydride, with a yield of 75.66% and a purity of 99.32%.
[0031] Example 3
[0032] In a 500 ml reaction flask, 200 g of pure water and 40 g of methanol were added; 31.5 g of sodium sulfite was added and stirred until dissolved; then 13.1 g of 1,3-dichloro-2-fluoropropane was added, and the temperature was raised to 80 °C. The mixture was refluxed for 12 h; a vacuum was slowly introduced to remove the solvent, obtaining a crude product of sodium 2-fluoro-1,3-propanedisulfonate and unreacted solid sodium sulfite.
[0033] The solid was slowly added to 250 g of phosphorus oxychloride, and the temperature was raised to 90 °C. The reaction was carried out for 4 h, and the unreacted phosphorus oxychloride was removed under reduced pressure to obtain a crude product of 4-fluoropropanedisulfonic anhydride.
[0034] 200 ml of acetone was added, and the temperature was raised to 60 °C. The mixture was filtered to remove the by-product sodium chloride. The filtrate was cooled to 0 - 5 °C and kept at this temperature for 1 h. Then, it was filtered by suction, and the filter cake was dried to obtain 14.25 g of the finished product of 4-fluoropropanedisulfonic anhydride, with a yield of 69.78% and a purity of 99.14%.
[0035] Example 4
[0036] In a 500 ml reaction flask, add 250 g of pure water and 50 g of tetrahydrofuran; add 31.5 g of sodium sulfite and stir to dissolve; then add 13.1 g of 1,3-dichloro-2-fluoropropane, heat up to 90 °C, and reflux for 12 h; slowly introduce vacuum to remove the solvent, obtaining crude sodium 2-fluoro-1,3-propanedisulfonate and solid sodium sulfite that has not reacted completely.
[0037] Slowly add the solid to 200 g of phosphorus trichloride, heat up to 90 °C, react for 4 h, and remove the unreacted phosphorus trichloride under reduced pressure to obtain crude 4-fluoropropanedisulfonic anhydride.
[0038] Add 200 ml of dichloromethane, heat up to 42 °C, filter to remove the by-product sodium chloride, cool the filtrate to 0 - 5 °C, keep warm for 1 h, carry out suction filtration, and dry the filter cake to obtain 13.71 g of finished 4-fluoropropanedisulfonic anhydride, with a yield of 67.14% and a purity of 99.21%.
[0039] Example 5
[0040] In a 500 ml reaction flask, add 200 g of pure water and 50 g of ethanol; add 25.2 g of sodium sulfite and stir to dissolve; then add 10.5 g of 1,3-dichloro-2-fluoropropane, heat up to 90 °C, and reflux for 12 h; slowly introduce vacuum to remove the solvent, obtaining crude sodium 2-fluoro-1,3-propanedisulfonate and solid sodium sulfite that has not reacted completely.
[0041] Slowly add the solid to 300 g of thionyl chloride, heat up to 90 °C, react for 4 h, and remove the unreacted thionyl chloride under reduced pressure to obtain crude 4-fluoropropanedisulfonic anhydride.
[0042] Add 200 ml of ethyl acetate, heat up to 60 °C, filter to remove the by-product sodium chloride, cool the filtrate to 0 - 5 °C, keep warm for 1 h, carry out suction filtration, and dry the filter cake to obtain 12.89 g of finished 4-fluoropropanedisulfonic anhydride, with a yield of 78.91% and a purity of 99.49%.
[0043] Finally, it should be noted that the above-described embodiments are only specific implementation manners of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the protection scope of the present invention.
Claims
1. A method for synthesizing 4-fluoropropanedisulfonic anhydride, characterized in that, It includes the following steps: S1. Using 1,3-dichloro-2-fluoropropane and sodium sulfite as starting materials, carry out a reflux reaction. After the reaction is completed, remove the solvent to obtain the crude product of sodium 2-fluoro-1,3-propanedisulfonate, and the molecular structural formula is S2. Add a dehydrating agent to carry out a dehydration reaction to obtain a crude product of 4-fluoropropanedisulfonic anhydride; S3. After recrystallization, the finished product of 4-fluoropropanedisulfonic anhydride is obtained, and its molecular structural formula is 2. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, The molar ratio of 1,3-dichloro-2-fluoropropane to sodium sulfite is 1:(2.3 - 3).
3. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, The solvent used in the reflux reaction is pure water, or a mixed solvent of pure water and one of ethanol, tetrahydrofuran, methanol, and acetone.
4. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, wherein The temperature of the reflux reaction is 40 - 120 °C, and the time of the reflux reaction is 2 - 24 h.
5. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, wherein, The dehydrating agent is selected from one or any combination of thionyl chloride, phosphorus trichloride, phosphorus oxychloride, phosphorus pentoxide, sulfuryl chloride, and triphosgene.
6. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, No solvent is used in the dehydration reaction, or the selected solvent is one of dichloromethane, dichloroethane, tetrahydrofuran, acetonitrile, and ethyl acetate.
7. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, The temperature of the dehydration reaction is 30 - 150 °C.
8. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, The addition amount of the dehydrating agent is 1 - 20 times that of the crude product of 2-fluoro-1,3-propanedisulfonic acid sodium salt.
9. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, The solvent for recrystallization is one of dichloromethane, dichloroethane, acetonitrile, ethyl acetate, acetone, and tetrahydrofuran.
10. The synthesis method of 4-fluoropropanedisulfonic anhydride according to claim 1, characterized in that, Use 1,3-dibromo-2-fluoropropane to replace 1,3-dichloro-2-fluoropropane.