A process for the preparation of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxathiolane)] 2,2,2',2'-tetraoxide

Abstract

This invention provides a method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide, relating to the field of organic compound synthesis technology. The method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide includes the following steps: S1, dissolving vinyl disulfate in a solvent to form a first system; S2, adding a halogenating agent to the first system at temperature T1, reacting at temperature T2 to obtain an intermediate, dissolving the intermediate in a solvent to form a second system; S3, adding a fluorinating agent to the second system at temperature T3, reacting at temperature T4 to obtain 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide. The preparation method provided by this invention yields 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide with high purity and few byproducts.

Description

Technical Field

[0001] This invention relates to the field of organic compound synthesis technology, and in particular to a method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide. Background Technology

[0002] Lithium-ion batteries have become the core energy source for portable electronic devices, electric vehicles, and large-scale energy storage systems due to their advantages such as high energy density, long cycle life, and low self-discharge rate.

[0003] As application scenarios place increasingly higher demands on battery performance (such as high voltage, high energy density, fast charging capability, and extreme temperature adaptability), traditional electrolyte systems face severe challenges in terms of electrode / electrolyte interface stability, thermal safety, and cycle life.

[0004] The electrolyte system consists of lithium salt, solvent, and additives. Lithium metal is present at the negative electrode during battery charging, where a reduction decomposition reaction occurs, increasing the battery's resistance and reducing its charge / discharge efficiency and energy density. At the positive electrode, the accumulation of degradation reactions continuously increases resistance, similarly leading to decreased battery performance. Additives are added to the electrolyte system to overcome these problems.

[0005] While prior art document CN 117069690 A discloses a method for preparing [4,4′-bis(1,3,2-dioxothiacyclopentane)]2,2,2′,2′-tetraoxide, this compound does not contain fluorine. In contrast, fluorine in 5,5′-difluoro-[4,4′-bis(1,3,2-dioxothiacyclopentane)]2,2,2′,2′-tetraoxide helps improve the electrochemical performance of lithium-ion batteries. There are few existing methods for synthesizing 5,5′-difluoro-[4,4′-bis(1,3,2-dioxothiacyclopentane)]2,2,2′,2′-tetraoxide, making it necessary to provide a method for preparing 5,5′-difluoro-[4,4′-bis(1,3,2-dioxothiacyclopentane)]2,2,2′,2′-tetraoxide. Summary of the Invention

[0006] Based on the technical problems existing in the background art, the present invention proposes a method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide.

[0007] The present invention proposes a method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide, comprising the following steps:

[0008] S1. Dissolve vinyl disulfate in a solvent to form the first system;

[0009] S2. Add a halogenated reagent to the first system at temperature T1, react at temperature T2 to obtain an intermediate, dissolve the intermediate in a solvent to form the second system;

[0010] S3. Add a fluorinated reagent to the second system at temperature T3 and react at temperature T4 to obtain 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide.

[0011] The operation method of this invention is simple and convenient, with high safety, low preparation cost and short cycle. The raw materials used are simple and readily available, and the prepared 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide has high purity and few by-products, and reduces pollution. It is an environmentally friendly preparation process.

[0012] Preferably, in S1 and S2, the solvent is selected from one or more of dichloromethane, 1,2-dichloroethane, toluene, cyclohexane, n-hexane, carbon tetrachloride, and chlorobenzene.

[0013] The role of the solvent is to provide the medium for the reaction, and it also affects the rate, selectivity and mechanism of the reaction through its physical and chemical properties.

[0014] Preferably, in S1, the mass-to-volume ratio of ethylene disulfate to solvent is 1g:5~30mL.

[0015] Within a certain range, the mass-to-volume ratio of ethylene disulfate to solvent can help improve the reaction rate and selectivity.

[0016] Preferably, in S2, the intermediate is a halodisulfate vinyl ester, namely 5,5'-dibromo-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide or 5,5'-dichloro-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide.

[0017] Preferably, in S2, the halogenated reagent is selected from one or more of sulfonyl chloride, sulfonium chloride, N-chlorosuccinimide, dibromo sulfonide, and N-bromosuccinimide.

[0018] The choice of halogenating reagent helps to improve product selectivity; the higher the reactivity of the halogen, the more vigorous the reaction and the lower the selectivity. If the fluorination reaction is carried out directly, the reaction is difficult to control; if the iodination reaction is chosen, the reaction is difficult to proceed due to the low reactivity of iodine. Therefore, the halogenating reagents mentioned in this invention are mostly reagents for chlorination and bromination reactions.

[0019] Preferably, in S2, the molar ratio of vinyl disulfate to halogenated reagent in the first system is 1:2.1~9.9.

[0020] In the first system, the molar ratio of vinyl disulfate to the halogenated reagent, within a certain range, helps to promote the reaction, increase the reaction rate and selectivity.

[0021] Preferably, in S2, the mass-to-volume ratio of the intermediate to the solvent is 1g:5~50mL.

[0022] Within a certain range, the mass-to-volume ratio of intermediates and solvents can help improve reaction rate and selectivity.

[0023] Preferably, in S2, T1 is -10~20℃ and T2 is 0~90℃.

[0024] Controlling the temperature range helps to improve reaction rate and selectivity.

[0025] Preferably, in step S2, the reaction time is 2 to 9 hours.

[0026] Preferably, in S3, the fluorinating agent is selected from one or more of sodium fluoride, potassium fluoride, and antimony trifluoride.

[0027] Choosing the right type of fluorinating agent can help improve product yield and reaction selectivity, and promote the reaction within a certain range.

[0028] Preferably, in S3, the molar ratio of the intermediate to the fluorinating agent in the second system is 1:2.2~4.8.

[0029] In the second system, a molar ratio of intermediate to fluorinating agent within a certain range can help improve product yield and reaction selectivity, and promote the reaction within a certain range.

[0030] Preferably, in S3, T3 is -5~15℃ and T4 is 20~80℃.

[0031] Controlling the temperature range helps to increase the reaction rate and promotes the reaction within a certain range.

[0032] Preferably, in step S3, the reaction time is 2 to 5 hours.

[0033] A 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide, prepared by the above method, has the following chemical structural formula: .

[0034] Application of the above-mentioned 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide or 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide in lithium-ion batteries.

[0035] The 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide prepared by this invention can be used as an additive for lithium-ion secondary batteries. It can form an excellent SEI film on the positive and negative electrode surfaces, improve battery impedance, and enhance the battery's storage and cycle performance.

[0036] The beneficial effects of this invention are as follows:

[0037] This invention uses vinyl disulfate as a reactant. The target product is obtained in two steps: a halogenated intermediate is generated through a halogenation reaction, followed by a fluorination reaction with a fluorinating agent. The method is simple, convenient, safe, low-cost, and quick. The raw materials used are readily available, and the prepared 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide has high purity, few byproducts, and reduced pollution, making it an environmentally friendly preparation process. Attached Figure Description

[0038] Figure 1 This invention provides the synthetic route for 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide.

[0039] Figure 2 The NMR fluorine spectrum of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide prepared in Example 1 of this invention.

[0040] Figure 3 The 1H NMR spectrum of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide prepared in Example 1 of this invention. Detailed Implementation

[0041] The technical solution of the present invention will be described in detail through specific embodiments.

[0042] Unless otherwise specified, all materials and reagents used in the following examples and comparative examples are commercially available.

[0043] Example 1

[0044] Preparation of 5,5'-dichloro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0045] 61.5 g of vinyl disulfate (0.25 mol) was added to a three-necked reaction flask and dissolved in 500 mL of dichloromethane. Sulfonyl chloride (81 g, 0.6 mol) was added dropwise over 3 h at -10 °C. The reaction was stirred at 40 °C for 6 h until complete. The dichloromethane solvent was removed by concentration. Water (300 mL) was added to the concentrate and stirred for 20 min. The mixture was filtered, and the filter cake was washed with anhydrous ethanol and dried under reduced pressure at 60 °C to obtain 68.7 g of product, with a yield of 87.3% and a purity of 99.14%.

[0046] Preparation of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0047] 63.0 g of 5,5'-dichloro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide (0.2 mol) was added to a reaction flask and dissolved in 600 mL of dichloromethane. Sodium fluoride (21 g, 0.5 mol) was added at 0 °C, and the mixture was stirred at 25 °C for 4 h. After filtration, the filtrate was concentrated, and anhydrous ethanol (150 mL) was added to the concentrate and stirred. The mixture was then filtered under vacuum, and the filter cake was dried under reduced pressure at 60 °C to obtain 51.2 g of product, with a yield of 90.9% and a purity of 99.37%.

[0048] Example 2

[0049] Preparation of 5,5'-dichloro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0050] 61.5 g of vinyl disulfate (0.25 mol) was added to a three-necked reaction flask and dissolved in 500 mL of dichloromethane. N-chlorosuccinimide (73.4 g, 0.55 mol) was added at 0 °C and stirred at 0 °C for 1 h. The temperature was then raised to 60 °C and stirred for 8 h. After the reaction was complete, the temperature was lowered to room temperature and filtered. The filtrate was concentrated, and water (300 mL) was added to the concentrate and stirred for 20 min. The mixture was then filtered under vacuum, and the filter cake was washed with anhydrous ethanol and dried under reduced pressure at 60 °C to obtain 60.8 g of product, with a yield of 77.2% and a purity of 99.21%.

[0051] Preparation of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0052] 63.0 g of 5,5'-dichloro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide (0.2 mol) was added to a reaction flask and dissolved in 600 mL of dichloromethane. Potassium fluoride (29 g, 0.5 mol) was added at 0 °C, and the mixture was stirred at 40 °C for 2 h. After filtration, the filtrate was concentrated. Anhydrous ethanol (150 mL) was added to the concentrate, and the mixture was stirred and filtered under vacuum. The filter cake was dried under reduced pressure at 60 °C to obtain 50.1 g of product, with a yield of 88.7% and a purity of 99.40%.

[0053] Example 3

[0054] Preparation of 5,5'-dibromo-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0055] 61.5 g of vinyl disulfate (0.25 mol) was added to a three-necked reaction flask and dissolved in 400 mL of 1,2-dichloroethane. N-bromosuccinimide (106.8 g, 0.6 mol) was added at 0 °C, and the mixture was stirred at 20 °C for 30 min. Then, the temperature was raised to 80 °C and stirred for 6 h. After the reaction was complete, the temperature was lowered to room temperature and filtered. The filtrate was concentrated, and water (300 mL) was added to the concentrate and stirred for 20 min. The mixture was then filtered under vacuum, and the filter cake was washed with anhydrous ethanol and dried under reduced pressure at 60 °C to obtain 63.3 g of product, with a yield of 80.4% and a purity of 99.18%.

[0056] Preparation of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide:

[0057] 80.8 g of 5,5'-dibromo-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide (0.2 mol) was added to a reaction flask and dissolved in 500 mL of 1,2-dichloroethane. Potassium fluoride (29 g, 0.5 mol) was added at 0 °C, and the mixture was stirred at 35 °C for 4 h. After filtration, the filtrate was concentrated, and anhydrous ethanol (150 mL) was added to the concentrate. The mixture was stirred, filtered, and the filter cake was dried under reduced pressure at 60 °C to obtain 48.8 g of product, with a yield of 86.5% and a purity of 99.26%.

[0058] Figure 1The synthetic route for 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide proposed in this invention demonstrates that the synthetic method of this invention is simple and convenient to operate. Figure 2 The NMR fluorine spectrum of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)] 2,2,2',2'-tetraoxide prepared in Example 1 of this invention shows that fluorine has been introduced into the structure. Figure 3 The 1H NMR spectrum of 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide prepared in Example 1 of this invention shows that it has the same number of equivalent hydrogens, which is different from the structure of fluorine-free vinyl disulfate.

[0059] In summary, the 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide provided by this invention has high purity, few byproducts, and reduces pollution, making it an environmentally friendly preparation process.

[0060] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention. It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be interchanged where appropriate so that the embodiments of the present application described herein can be implemented, for example, in orders other than those described herein.

Claims

1. A method for preparing 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide, characterized in that, Includes the following steps: S1. Dissolve vinyl disulfate in a solvent to form the first system; S2. Add a halogenated reagent to the first system at temperature T1, react at temperature T2 to obtain an intermediate, dissolve the intermediate in a solvent to form the second system; S3. Add a fluorinated reagent to the second system at temperature T3 and react at temperature T4 to obtain 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide.

2. The preparation method according to claim 1, characterized in that, In S1, the mass-to-volume ratio of ethylene disulfate to solvent is 1 g: 5~30 mL.

3. The preparation method according to claim 1, characterized in that, In S2, the halogenated reagent is selected from one or more of sulfonyl chloride, sulfonium chloride, N-chlorosuccinimide, dibromo sulfonide, and N-bromosuccinimide.

4. The preparation method according to claim 1, characterized in that, In S2, the molar ratio of vinyl disulfate to halogenated reagent in the first system is 1:2.1~9.

9.

5. The preparation method according to claim 1, characterized in that, In the S2, the mass-to-volume ratio of the intermediate to the solvent is 1g:5~50mL.

6. The preparation method according to claim 1, characterized in that, In the S2 process, T1 is -10~20℃, T2 is 0~90℃, and the reaction time is 2~9h.

7. The preparation method according to claim 1, characterized in that, In S1 and S2, the solvent is selected from one or more of dichloromethane, 1,2-dichloroethane, toluene, cyclohexane, n-hexane, carbon tetrachloride, and chlorobenzene.

8. The preparation method according to claim 1, characterized in that, In S3, the fluorinating agent is selected from one or more of sodium fluoride, potassium fluoride, and antimony trifluoride; the molar ratio of the intermediate to the fluorinating agent in the second system is 1:2.2~4.

8.

9. The preparation method according to claim 1, characterized in that, In the S3 process, T3 is -5~15℃, T4 is 20~80℃, and the reaction time is 2~5h.

10. A 5,5'-difluoro-[4,4'-bis(1,3,2-dioxothiacyclopentane)]2,2,2',2'-tetraoxide, characterized in that, The preparation method according to any one of claims 1 to 9 is used to obtain the following chemical structural formula: .

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