Process for the preparation of pentaerythritol bis-cyclic sulphate

Abstract

The application provides a preparation method of pentaerythritol bicyclic sulfate. The preparation method of the pentaerythritol bicyclic sulfate comprises the following steps: mixing pentaerythritol and sulfuryl chloride in a solvent, and performing a substitution reaction under the catalysis of imidazole to obtain pentaerythritol bicyclic sulfate. The preparation method of the pentaerythritol bicyclic sulfate provided in the application has the advantages of cheap and easily available raw materials, simple process, safe operation, a yield of greater than or equal to 82%, and wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic synthesis, and particularly relates to a preparation method of pentaerythritol bicyclic sulfate. BACKGROUND

[0002] Pentaerythritol bicyclic sulfate, the chemical name of which is 2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane 3,3,9,9-tetraoxide, is an organic synthesis raw material and can be used as a lithium ion secondary battery electrolyte additive. The pentaerythritol bicyclic sulfate can form a more optimal SEI protective layer on the positive and negative electrode surfaces, avoids the oxidative decomposition of the electrolyte under high pressure, and the SEI film on the positive and negative electrode surfaces has high stability and high conductivity, thereby increasing the cycle life of the battery.

[0003] In recent years, lithium secondary batteries have a very broad application prospect in electronics, batteries and energy due to the advantages of high energy density, long cycle life and no pollution. However, the lithium ion battery is prone to gas production under high temperature conditions, which causes the battery to swell or the internal pressure to be too large, thereby causing great safety hazards of the battery and greatly reducing the service life of the battery. In order to solve the problem of gas production of the lithium battery under high temperature, some bicyclic sulfate additives are usually added to the electrolyte. The additives can form an SEI film on the positive and negative electrode surfaces of the lithium battery to inhibit the gas production of the battery under high temperature, further inhibit the initial capacity decline of the battery, improve the cycle life of the battery, and improve the high and low temperature charging and discharging performance of the battery.

[0004] In view of the excellent performance and application range of pentaerythritol bicyclic sulfate, it is very worthy of development.

[0005] There are few synthesis methods of pentaerythritol bicyclic sulfate. Turan Ozturk, b Nezire Saygili, et al. (J. Chem. Soc., Perkin Trans. 1, 2001, 407-414) reported that 2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane 3,9-dioxide was prepared from pentaerythritol and thionyl chloride as raw materials, with a yield of 61%. 2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5]undecane 3,9-dioxide was subjected to the action of ruthenium trichloride and sodium periodate to obtain the target product pentaerythritol bicyclic sulfate, with a yield of 87%. The raw materials ruthenium trichloride and sodium periodate are expensive, the cost is increased, and the industrial production is not easy. The total yield is 53%, and the synthesis route is as follows:

[0006]

[0007] CN110156811A reports the preparation of pentaerythritol bicyclic sulfate by reacting pentaerythritol with dimethyl sulfate in benzene as solvent and titanate as catalyst at a reaction temperature of 120-150℃. This method employs a one-step approach, which, while simple, suffers from low yield, the highly toxic dimethyl sulfate, and the carcinogenic benzene solvent. Furthermore, the high reaction temperature and high production pressure necessitate stringent safety and production requirements. No yield report has been found. The synthetic route is as follows:

[0008]

[0009] In view of this, the present invention is hereby proposed. Summary of the Invention

[0010] The main objective of this invention is to provide a method for preparing pentaerythritol bicyclic sulfate, which solves the problems of high raw material costs and low yields in the prior art when using pentaerythritol and thionyl chloride as raw materials; and the high safety and production requirements when using pentaerythritol and dimethyl sulfate as raw materials, as the raw materials are highly toxic or carcinogenic.

[0011] To achieve the above objectives, according to one aspect of the present invention, a method for preparing pentaerythritol bicyclic sulfate is provided, the method comprising: mixing pentaerythritol and sulfonyl chloride in a solvent and carrying out a substitution reaction under the catalysis of imidazole to obtain pentaerythritol bicyclic sulfate.

[0012] Furthermore, the molar ratio of pentaerythritol, imidazole, and sulfonyl chloride is 1:(4.1–8.8):(2.1–4.2).

[0013] Furthermore, the substitution reaction is carried out at a temperature of 15–25°C for a time of 1.5–3 hours.

[0014] Furthermore, the solvent is an organic solvent, including at least one of dichloromethane, tetrahydrofuran, N,N-dimethylformamide, and toluene, preferably dichloromethane.

[0015] Furthermore, the substitution reaction is carried out under the protection of an inert gas, including at least one of argon, helium, or nitrogen.

[0016] Further, the preparation method of the pentaerythritol bicyclic sulfate includes: step S1, dispersing sulfonyl chloride in a solvent to obtain a sulfonyl chloride solution; dispersing pentaerythritol in a solvent to obtain a pentaerythritol solution; dispersing imidazole in a solvent to obtain an imidazole solution; step S2, mixing the sulfonyl chloride solution, pentaerythritol solution, and imidazole solution under an inert gas protection to carry out a substitution reaction to obtain a reaction solution of pentaerythritol bicyclic sulfate; step S3, purifying the reaction solution of pentaerythritol bicyclic sulfate to obtain pentaerythritol bicyclic sulfate.

[0017] Further, step S2 includes: step S21, first adding sulfonyl chloride solution dropwise to imidazole solution at 0-5℃, then heating to 15-30℃ and mixing for 1.5-3h to obtain a mixed solution of sulfonyl chloride and imidazole; step S22, first cooling the fused solution of sulfonyl chloride and imidazole to 0-5℃, then adding pentaerythritol solution dropwise to the mixed solution of sulfonyl chloride and imidazole, then heating to 15-30℃ and mixing for 1.5-3h to carry out a substitution reaction to obtain a reaction solution of pentaerythritol bicyclic sulfate.

[0018] Further, step S3 includes: step S31, filtering the reaction solution of pentaerythritol dicyclic sulfate to obtain a filter cake and a filtrate; step S32, washing the filter cake with water and drying it to obtain pentaerythritol dicyclic sulfate.

[0019] Furthermore, step S3 also includes: step S33, washing the filtrate sequentially with dilute hydrochloric acid and water, and then performing vacuum distillation to recover the solvent in the filtrate.

[0020] Furthermore, the solvent recovered in step S33 is returned to step S1 for continued use.

[0021] The method for preparing pentaerythritol bicyclic sulfate provided in this application uses inexpensive and readily available raw materials, has a simple process, is safe to operate, and has a yield of ≥82%, making it suitable for large-scale production and having broad application prospects. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0023] Figure 1 The NMR spectrum of the pentaerythritol bicyclic sulfate product provided in Example 1 of the present invention is shown; and

[0024] Figure 2 The infrared spectrum of the pentaerythritol bicyclic sulfate product provided in Example 1 of the present invention is shown. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0026] As analyzed in the background section of this application, the existing technology for preparing pentaerythritol dicyclic sulfate using pentaerythritol and thionyl chloride as raw materials suffers from high raw material costs and low yields; while using pentaerythritol and dimethyl sulfate as raw materials presents the problem of highly toxic or carcinogenic raw materials, posing significant safety and production requirements. To address these issues, this application provides a method for preparing pentaerythritol dicyclic sulfate.

[0027] In one typical embodiment of this application, a method for preparing pentaerythritol dicyclic sulfate is also provided. The method includes mixing pentaerythritol and sulfonyl chloride in a solvent and carrying out a substitution reaction under the catalysis of imidazole to obtain pentaerythritol dicyclic sulfate.

[0028] The method for preparing pentaerythritol bicyclic sulfate provided in this application uses inexpensive and readily available raw materials, has a simple process, is safe to operate, and has a yield of ≥82%, making it suitable for large-scale production and with broad application prospects.

[0029] The possible reaction mechanism for the synthesis of pentaerythritol bicyclic sulfate provided in this application is shown in the figure below.

[0030]

[0031] Thionyl chloride forms transition state 1 under the action of imidazole, and further forms intermediate 1 under the action of imidazole. Intermediate 1 reacts with pentaerythritol to form transition state 2, and further forms transition state 3. Transition state 3 undergoes intramolecular nucleophilic addition to give pentaerythritol bicyclic sulfate.

[0032] To further reduce raw material waste and improve the yield of pentaerythritol bicyclic sulfate, the preferred molar ratio of pentaerythritol, imidazole and sulfonyl chloride is 1:(4.1-8.8):(2.1-4.2).

[0033] In this application, with pentaerythritol used as 1 mol, the amount of imidazole used is 4.1 mol, 4.2 mol, 4.5 mol, 4.8 mol, 5.0 mol, 5.5 mol, 6.0 mol, 6.5 mol, 6.8 mol, 7.0 mol, 7.5 mol, 8.0 mol, 8.5 mol, 8.8 mol, or any two of these values; the amount of sulfonyl chloride used is 2.1 mol, 2.2 mol, 2.5 mol, 2.8 mol, 3.0 mol, 3.2 mol, 3.5 mol, 3.8 mol, 4.0 mol, 4.2 mol, or any two of these values.

[0034] To further reduce operating energy consumption, the preferred temperature for the above substitution reaction is 15–25°C (e.g., 15°C, 18°C, 20°C, 22°C, 25°C or any combination of two values), and the preferred time is 1.5–3 h (e.g., 1.5 h, 1.8 h, 2.0 h, 2.2 h, 2.5 h, 2.8 h, 3.0 h or any combination of two values).

[0035] The specific type of solvent is not limited; any solvent capable of dispersing imidazole, pentaerythritol, or sulfonyl chloride is acceptable. For ease of recycling, a single solvent is preferred. From the perspective of safety, environmental protection, and pollution reduction, dichloromethane is the preferred solvent.

[0036] To further improve the yield of the aforementioned pentaerythritol bicyclic sulfate, it is preferable to carry out the substitution reaction under an inert gas atmosphere to avoid introducing impurity ions. The specific type of inert gas is not limited, and includes, but is not limited to, any one or more of argon, argon, or nitrogen in mixtures.

[0037] In some specific embodiments of this application, pentaerythritol bicyclic sulfate is prepared according to the following steps:

[0038] Step S1: Disperse sulfonyl chloride in a solvent to obtain a sulfonyl chloride solution; disperse pentaerythritol in a solvent to obtain a pentaerythritol solution; disperse imidazole in a solvent to obtain an imidazole solution;

[0039] Step S2: The sulfonyl chloride solution, pentaerythritol solution and imidazole solution are mixed under inert gas protection to carry out a substitution reaction, thereby obtaining the reaction solution of pentaerythritol bicyclic sulfate.

[0040] Step S3: Purify the reaction solution of pentaerythritol bicyclic sulfate to obtain pentaerythritol bicyclic sulfate.

[0041] To further simplify the purification process, dichloromethane is preferred as the solvent.

[0042] In step S1 above, in order to further improve the efficiency of the substitution reaction and reduce solvent waste, the molar concentration of the sulfonyl chloride solution is preferably 1-2 mol / L, more preferably 1.5 mol / L; the molar concentration of the pentaerythritol solution is 3-3.5 mol / L, more preferably 3.33 mol / L; and the molar concentration of the imidazole solution is 1-2 mol / L, preferably 1.55 mol / L.

[0043] To further improve the yield of pentaerythritol bicyclic sulfate and reduce the occurrence of side reactions, step S2 preferably includes:

[0044] Step S21: First, add sulfonyl chloride solution dropwise to imidazole solution at 0-5℃ (e.g., 0, 1℃, 2℃, 3℃, 5℃ or any two of these values), then raise the temperature to 15-30℃ (e.g., 15℃, 18℃, 20℃, 25℃, 30℃ or any two of these values) and mix for 1.5-3h (1.5h, 1.8h, 2.0h, 2.5h, 3.0h or any two of these values) to obtain a mixed solution of sulfonyl chloride and imidazole.

[0045] In step S22, the mixed solution of sulfonyl chloride and imidazole is first cooled to 0-5℃ (e.g., 0, 1℃, 2℃, 3℃, 5℃ or any two of these values). Then, pentaerythritol solution is added dropwise to the mixed solution of sulfonyl chloride and imidazole. The temperature is then raised to 15-30℃ (e.g., 15℃, 18℃, 20℃, 25℃, 30℃ or any two of these values) and mixed for 1.5-3 hours (1.5 hours, 1.8 hours, 2.0 hours, 2.5 hours, 3.0 hours or any two of these values) to carry out the substitution reaction and obtain the reaction solution of pentaerythritol bicyclic sulfate.

[0046] To further improve the purification efficiency of the pentaerythritol dicyclic sulfate reaction solution and reduce the number of steps, step S3 is preferably defined as follows:

[0047] Step S31: The reaction solution of pentaerythritol bicyclic sulfate is filtered to obtain filter cake and filtrate;

[0048] Step S32: Wash the filter cake with water and dry it to obtain pentaerythritol bicyclic sulfate.

[0049] In step S32 above, to accelerate the washing efficiency of water, rinsing is preferred. To further reduce energy consumption, the drying temperature is preferably 75-85°C (e.g., 75°C, 78°C, 80°C, 82°C, 85°C, or any range of two values).

[0050] To further conserve energy, step S3 also includes: step S33, where the filtrate is washed sequentially with dilute hydrochloric acid and water, and then subjected to vacuum distillation to recover the solvent from the filtrate. In particular, returning the recovered solvent to step S1 for reuse further reduces energy consumption.

[0051] The preferred mass concentration of the above-mentioned dilute hydrochloric acid is 1% to 10% (e.g., 1%, 2%, 5%, 8% or 10%), in order to further improve the washing efficiency.

[0052] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0053] Example 1

[0054] This embodiment provides a pentaerythritol bicyclic sulfate product, which is prepared according to the following steps:

[0055] (1) Disperse sulfonyl chloride (59.4 g, 0.44 mol) in dichloromethane (300 mL) to obtain sulfonyl chloride solution; disperse pentaerythritol (27.2 g, 0.20 mol) in dichloromethane (60 mL) to obtain pentaerythritol solution; under argon atmosphere, add dichloromethane (800 mL) and imidazole (62.6 g, 0.92 mol) to the reaction flask, cool to 0-5 °C, and add sulfonyl chloride (59.4 g, 0.44 mol) solution dropwise over 10 min with stirring. After addition, stir at 20 °C for 2 hours to obtain a mixed solution of sulfonyl chloride and imidazole.

[0056] (2) First, cool the mixed solution of sulfonyl chloride and imidazole to 0-5℃, then add pentaerythritol solution dropwise to the mixed solution of sulfonyl chloride and imidazole. After the addition is complete, heat to 20℃ and stir for 2 hours to carry out the substitution reaction to obtain the reaction solution of pentaerythritol bicyclic sulfate.

[0057] (3) The reaction solution of pentaerythritol dicyclic sulfate was filtered to obtain a filter cake and a filtrate. The filter cake was washed with water (60 mL) and dried to obtain the pentaerythritol dicyclic sulfate product. The filtrate was washed successively with dilute hydrochloric acid (5% concentration, 300 mL) and water (300 mL), and then dichloromethane was recovered by vacuum distillation.

[0058] Example 2

[0059] The difference between this embodiment and Example 1 is that the amount of imidazole used is 0.82 mol and the amount of sulfonyl chloride used is 0.84 mol.

[0060] Example 3

[0061] The difference between this embodiment and Example 1 is that the amount of imidazole used is 1.76 mol and the amount of sulfonyl chloride used is 0.42 mol.

[0062] Example 4

[0063] The difference between this embodiment and embodiment 1 is that in step (2), the temperature for the substitution reaction is 15°C and the time is 3 hours.

[0064] Example 5

[0065] The difference between this embodiment and embodiment 1 is that in step (3), the temperature for the substitution reaction is 25°C and the time is 1.5h.

[0066] Example 6

[0067] The difference between this embodiment and embodiment 1 is that in step (2), the temperature for the substitution reaction is 10°C and the time is 2 hours.

[0068] Example 7

[0069] The difference between this embodiment and embodiment 1 is that in step (3), the temperature for the substitution reaction is 50°C and the time is 2 hours.

[0070] Example 8

[0071] The difference between this embodiment and Example 1 is that the amount of imidazole used is 0.4 mol.

[0072] Example 9

[0073] The difference between this embodiment and Example 1 is that the amount of sulfonyl chloride used is 0.3 mol.

[0074] Example 10

[0075] The difference between this embodiment and Example 1 is that the dichloromethane used in this embodiment is the dichloromethane recovered from the filtrate in Example 1.

[0076] Experimental Example 1

[0077] The pentaerythritol bicyclic sulfate product provided in Example 1 was subjected to NMR and IR detection, and the resulting spectra are shown below. Figure 1 and Figure 2 As shown.

[0078] Figure 1 middle, 1 H NMR (400MHz, DMSO-d6): δ (ppm): 4.93 (s, 8H); Figure 2 In the mean IRνmax: 1397.8, 1210.6, 1143.6, 1032.7, 979.9, 814.6, 773.9, 570.5, 531.9 cm -1 It can be seen that the pentaerythritol bicyclic sulfate product provided in Example 1 is consistent with the preset structure.

[0079] Experimental Example 2

[0080] The pentaerythritol bicyclic sulfate products prepared in Examples 1-10 were tested for yield, and the results are shown in Table 1 below. The yield was calculated based on the molar amount of pentaerythritol.

[0081] Table 1

[0082] Yield (%) Example 1 82 Example 2 80 Example 3 81 Example 4 82 Example 5 81 Example 6 76 Example 7 65 Example 8 72 Example 9 66 Example 10 81

[0083] As can be seen from the above description, the above embodiments of the present invention achieve the following technical effects: By applying the technical solution of this application, the preparation method of pentaerythritol bicyclic sulfate provided by this application has inexpensive and readily available raw materials, a simple process, safe operation, and a yield of ≥82%, which is suitable for large-scale production and has broad application prospects.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A process for the preparation of pentaerythritol bis-cyclic sulfate characterized in that, The preparation method comprises: mixing pentaerythritol and sulfonyl chloride in a solvent, and performing a substitution reaction under catalysis of imidazole to obtain pentaerythritol bis-cyclic sulfate; The molar ratio of the pentaerythritol, the imidazole and the sulfonyl chloride is 1:(4.1-8.8):(2.1-4.2). The temperature of the substitution reaction is 15-25 DEG C, and the time is 1.5-3h.

2. The production method according to claim 1, characterized by, The solvent is an organic solvent, and the organic solvent is selected from at least one of dichloromethane, tetrahydrofuran, N,N-dimethylformamide and toluene.

3. The production method according to claim 2, characterized by, The organic solvent is dichloromethane.

4. The preparation method according to claim 1, characterized in that, The substitution reaction is performed under protection of an inert gas or nitrogen, and the inert gas is selected from at least one of argon and helium.

5. The production method according to any one of claims 1 to 4, characterized by, The preparation method comprises: Step S1, dispersing the sulfonyl chloride in a solvent to obtain a sulfonyl chloride solution, dispersing the pentaerythritol in a solvent to obtain a pentaerythritol solution, and dispersing the imidazole in a solvent to obtain an imidazole solution; Step S2, mixing the sulfonyl chloride solution, the pentaerythritol solution and the imidazole solution under protection of an inert gas to perform the substitution reaction to obtain a reaction liquid of the pentaerythritol bis-cyclic sulfate; Step S3, purifying the reaction liquid of the pentaerythritol bis-cyclic sulfate to obtain the pentaerythritol bis-cyclic sulfate.

6. The production method according to claim 5, wherein The step S2 comprises: Step S21, first adding the sulfonyl chloride solution to the imidazole solution dropwise at 0-5 DEG C, then warming to 15-30 DEG C and mixing for 1.5-3h to obtain a mixed solution of sulfonyl chloride and imidazole; Step S22, first cooling the mixed solution of sulfonyl chloride and imidazole to 0-5 DEG C, then adding the pentaerythritol solution to the mixed solution of sulfonyl chloride and imidazole dropwise, then warming to 15-25 DEG C and mixing for 1.5-3h to perform the substitution reaction to obtain the reaction liquid of the pentaerythritol bis-cyclic sulfate.

7. The preparation method according to claim 5, characterized in that, The step S3 comprises: Step S31, performing suction filtration on the reaction liquid of the pentaerythritol bis-cyclic sulfate to obtain a filter cake and a filtrate; Step S32, washing the filter cake with water and drying to obtain the pentaerythritol bis-cyclic sulfate.

8. The preparation method according to claim 7, characterized in that, The step S3 further comprises: step S33, washing the filtrate with dilute hydrochloric acid and water in sequence, and then performing reduced-pressure distillation to recover the solvent in the filtrate.

9. The production method according to claim 8, characterized by, The solvent recovered in the step S33 is returned to the step S1 for continuous use.

Images