Preparation method of erythritol sulfate

Abstract

The invention relates to the technical field of organic synthesis, in particular to a preparation method of erythritol sulfate. The preparation method of erythritol sulfate provided by the invention comprises the following two key steps: firstly, carrying out chlorination reaction on ethylene sulfate and chlorine under the catalysis of ultraviolet light to generate chloroethylene sulfate, and then carrying out dechlorination coupling reaction on the chloroethylene sulfate under the action of metal powder such as copper powder, zinc powder, iron powder and magnesium powder to obtain the erythritol sulfate. And the erythritol sulfate is prepared. Compared with the prior art, the novel method for preparing erythritol sulfate provided by the invention has the advantages that the use of sodium hypochlorite is avoided, and the generation of wastewater is reduced; moreover, the method provided by the invention has the advantages of mild reaction conditions, easily available raw materials and high reaction selectivity, the generation of byproducts can be effectively controlled in the reaction process, and the production efficiency and the product purity of the erythritol sulfate are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly relates to a preparation method of erythritol sulfate. Background Art

[0002] In recent years, with the rapid development of the new energy vehicle market in China, the demand for lithium batteries has increased significantly. As the market's requirements for the energy performance of lithium batteries continue to improve, by adding a small amount of additives to the electrolyte of lithium-ion batteries, certain battery performances can be targeted improved, such as reversible capacity, electrode / electrolyte compatibility, cycle performance, rate performance, and safety performance. Functional additives for lithium-ion battery electrolytes play a very crucial role in lithium-ion batteries and are an indispensable component of lithium batteries, and their research and development have attracted much attention.

[0003] According to the different functions of additives, they can be divided into SEI film-forming additives, flame retardant additives, overcharge protection additives, high and low temperature additives, etc. Among them, erythritol sulfate is a typical additive for lithium electrolytes of organic sulfates. It can inhibit the decline of the initial capacity of the battery, increase the initial discharge capacity, reduce the battery swelling after high-temperature storage, and improve the charge and discharge performance and cycle times of the battery. As one of the cyclic ethylene sulfates, erythritol sulfate has broad market demand and development prospects.

[0004] At present, erythritol sulfate is mainly prepared by directly sulfating erythritol, oxidizing erythritol sulfite with sodium hypochlorite and other methods. However, these methods often have disadvantages such as harsh reaction conditions, many by-products, and difficulty in controlling purity and yield. Even the most mainstream method of oxidizing erythritol sulfite at present requires high temperature and strong acid or strong base conditions. These conditions not only produce a large amount of wastewater and cause serious pollution to the environment, but also the yield and purity of the product are not high.

[0005] Therefore, developing a new preparation method of erythritol sulfate, while reducing environmental pollution, improving the production efficiency and product purity of erythritol sulfate, has important significance for industrial production. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a preparation method of erythritol sulfate with high product purity, low impurity content and suitable for industrial production.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] The preparation method of erythritol sulfate provided by the present invention includes two key steps: First, vinyl sulfate reacts with chlorine to generate vinyl chlorosulfate through a chlorination reaction, and then a dechlorination coupling reaction is carried out under the action of metal powders such as copper powder, zinc powder, iron powder, and magnesium powder to prepare erythritol sulfate. The reaction mechanism of this method is as follows:

[0009]

[0010] In the above formula, M is a metal catalyst, which can be any one of copper powder, zinc powder, iron powder, and magnesium powder.

[0011] Furthermore, the preparation method of erythritol sulfate provided by the present invention includes the following steps:

[0012] S1 Preparation of vinyl chlorosulfate: First, dissolve vinyl sulfate in an organic solvent, heat it to a temperature of 50 - 100 °C, then introduce chlorine gas, and carry out the reaction under the catalysis of ultraviolet light to obtain vinyl chlorosulfate;

[0013] S2 Preparation of erythritol sulfate: Under the action of a metal catalyst, the vinyl chlorosulfate prepared in S1 undergoes a dechlorination coupling reaction to prepare erythritol sulfate, and the metal catalyst is selected from any one of copper powder, zinc powder, iron powder, and magnesium powder.

[0014] In the above preparation method of erythritol sulfate, preferably, the reaction temperature in S1 is 60 - 80 °C.

[0015] Preferably, the organic solvent in S1 is selected from any one of chloroform and carbon tetrachloride. Preferably, the mass of the organic solvent in S1 is 5 - 20 times the mass of vinyl sulfate, and the molar ratio of chlorine gas to vinyl sulfate is 1.0 - 1.5:1.

[0016] More preferably, the mass of the organic solvent in S1 is 10 - 12 times the mass of vinyl sulfate, and the molar ratio of chlorine gas to vinyl sulfate is 1.2:1.

[0017] Preferably, the wavelength of the ultraviolet light in S1 is 250 - 400 nm.

[0018] More preferably, the wavelength of the ultraviolet light in S1 is 365 nm.

[0019] Preferably, the molar ratio of the metal catalyst to vinyl chlorosulfate in S2 is 0.5 - 4:1.

[0020] More preferably, the molar ratio of the metal catalyst to vinyl chlorosulfate in S2 is 2:1.

[0021] Preferably, the reaction temperature of the dechlorination coupling reaction described in S2 is 50 to 120 °C.

[0022] More preferably, the reaction temperature of the dechlorination coupling reaction described in S2 is 80 to 90 °C.

[0023] Preferably, for the dechlorination coupling reaction described in S2, at least one of tetrahydrofuran, acetone, cyclohexane, benzene, toluene, and xylene is used as the reaction solvent.

[0024] More preferably, the dechlorination coupling reaction described in S2 uses tetrahydrofuran as the reaction solvent.

[0025] Preferably, after the dechlorination coupling reaction in S2, a reaction mixture is obtained. The reaction mixture is respectively subjected to desolvation, water washing, recrystallization, and drying treatments to obtain purified erythritol sulfate.

[0026] Preferably, for the recrystallization described in S2, at least one of petroleum ether, dichloromethane, n-hexane, methyl acetate, ethyl acetate, dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate is used as the recrystallization solvent.

[0027] As a further preference, the recrystallization described in S2 uses dimethyl carbonate as the solvent.

[0028] More specifically, a method for preparing erythritol sulfate provided by the present invention includes the following steps:

[0029] S1 Preparation of vinyl chlorosulfate: First, dissolve vinyl sulfate in an organic solvent, heat to a temperature of 50 to 100 °C, then introduce chlorine gas, and carry out the reaction under the catalysis of ultraviolet light with a wavelength of 250 to 400 nm to obtain vinyl chlorosulfate. Among them, the organic solvent is chloroform or carbon tetrachloride, the mass of the organic solvent is 5 to 20 times the mass of vinyl sulfate, and the molar ratio of chlorine gas to vinyl sulfate is 1.0 to 1.5:1;

[0030] S2 Preparation of erythritol sulfate: Under the action of a metal catalyst, the chlorosulfate prepared in S1 undergoes a dechlorination coupling reaction at 50 to 120 °C. After the reaction ends, a reaction mixture is obtained, and after respectively undergoing desolvation, water washing, recrystallization, and drying treatments, purified erythritol sulfate is obtained. The metal catalyst is selected from any one of copper powder, zinc powder, iron powder, and magnesium powder.

[0031] The beneficial effects of the present invention are as follows:

[0032] Compared with the prior art, the new method for preparing erythritol sulfate provided by the present invention generates vinyl chlorosulfate by reacting vinyl sulfate with chlorine gas, and then through dechlorination coupling reaction, not only avoids the use of sodium hypochlorite and reduces the generation of wastewater; moreover, the method of the present invention has mild reaction conditions, easily obtainable raw materials, high reaction selectivity, and can significantly reduce the water content and product acidity in the product during the reaction process. The production efficiency and product purity of erythritol sulfate are both significantly improved. The purity of the erythritol sulfate product obtained by this method is greater than 99.5%, and the yield is greater than 82%. In addition, the method provided by the present invention is applicable to industrial-scale production and has significant economic and application values. Detailed Embodiments

[0033] In order to enable those skilled in the art to better understand the present invention, the present invention will be further elaborated below in conjunction with specific embodiments.

[0034] Example 1

[0035] S1 Preparation of vinyl chlorosulfate: In a 250 mL quartz photoreactor, add 12.4 g of vinyl sulfate (0.1 mol), 150 mL of chloroform, heat to 70 °C, introduce 0.12 mol of chlorine gas, and react under ultraviolet light irradiation with a wavelength of 365 nm for 4 h. After monitoring the reaction by gas chromatography until it ends, cool down, concentrate, and distill to obtain 14.53 g of vinyl chlorosulfate, with a yield of 88% and a purity of 96%.

[0036] S2 Preparation of erythritol sulfate: In a 250 mL three-necked flask, add 120 mL of tetrahydrofuran, 7.9 g of vinyl chlorosulfate (0.05 mol), and 6.5 g of zinc powder, heat to reflux, and carry out the dechlorination coupling reaction at 65 °C. After reacting for 1 h, obtain the reaction mixture. Filter the reaction mixture, concentrate the filtrate, add 120 mL of dimethyl carbonate to the residue, heat to dissolve, and wash with deionized water three times. Finally, directly cool and crystallize in dimethyl carbonate, filter the crystals, and after vacuum drying, obtain 5.56 g of erythritol sulfate, with a yield of 90% and a purity of 99.6%.

[0037] Example 2

[0038] S1 Preparation of vinyl chlorosulfate: In a 250 mL quartz photoreactor, add 12.4 g of vinyl sulfate (0.1 mol), 150 mL of carbon tetrachloride, heat to 80 °C, introduce 0.12 mol of chlorine gas, and react under ultraviolet light irradiation with a wavelength of 365 nm for 4 h. After monitoring the reaction by gas chromatography until it ends, cool down, concentrate, and distill to obtain 13.75 g of vinyl chlorosulfate, with a yield of 85% and a purity of 98%.

[0039] Preparation of erythritol sulfate: In a 250 mL three-necked flask, add 120 mL of toluene, 7.9 g of vinyl chlorosulfate (0.05 mol), and 6.5 g of zinc powder. Heat under reflux and carry out a dechlorination coupling reaction at 110 °C. After reacting for 1 h, filter the reaction mixture, concentrate the filtrate, add 120 mL of dimethyl carbonate to the residue, heat to dissolve, and wash with deionized water three times. Finally, cool and crystallize directly in dimethyl carbonate, filter the crystals, and obtain 5.4 g of erythritol sulfate after vacuum drying. The yield is 83%, and the purity is 94.6%.

[0040] Example 3

[0041] S1 Preparation of vinyl chlorosulfate: In a 250 mL quartz photoreactor, add 12.4 g of vinyl sulfate, 150 mL of chloroform, heat to 75 °C, introduce 0.15 mol of chlorine gas, and react under the irradiation of ultraviolet light with a wavelength of 365 nm for 4 h. After monitoring the end of the reaction by gas chromatography, cool down, concentrate, and distill to obtain 14.52 g of vinyl chlorosulfate. The yield is 78.8%, and the purity is 86%.

[0042] S2 Preparation of erythritol sulfate: In a 250 mL three-necked flask, add 120 mL of benzene, 7.9 g of vinyl chlorosulfate (0.05 mol), and 6.5 g of zinc powder. Heat under reflux and carry out a dechlorination coupling reaction at 80 °C for 1 h. After the reaction is completed, filter the reaction mixture, concentrate the filtrate, add 120 mL of dimethyl carbonate to the residue, heat to dissolve, and wash with deionized water three times. Finally, cool and crystallize in ethyl acetate, filter the crystals, and obtain 6.08 g of erythritol sulfate after vacuum drying. The yield is 85%, and the purity is 86%.

[0043] Example 4

[0044] The difference from Example 1 is that in S1, the wavelengths of ultraviolet light are set to 250 nm and 320 nm respectively.

[0045] Example 5

[0046] The difference from Example 1 is that the reaction times in S1 are controlled to be 3 h and 5 h respectively.

[0047] The yields and purities of the intermediate vinyl chlorosulfate obtained in Examples 1 - 5 are shown in Table 1 below.

[0048] Table 1 Statistics of the yields and purities of the intermediate vinyl chlorosulfate

[0049]

[0050] Example 6

[0051] It is different from Example 1 in that the molar ratio of the metal catalyst to vinyl sulfite chloride in S2 is 1:1 or 3:1.

[0052] Example 7

[0053] It is different from Example 1 in that the metal catalysts used in S2 are magnesium powder and copper powder respectively.

[0054] Example 8

[0055] It is different from Example 1 in that the organic solvents used in S2 are acetone and cyclohexane respectively.

[0056] The yields and purities of the final product erythritol sulfate obtained in Examples 1-3 and Examples 6-8 are shown in Table 2 below.

[0057] Table 2 Statistics of the yields and purities of the final product erythritol sulfate obtained under different conditions

[0058]

Claims

1. A method for preparing erythritol sulfate, characterized in that: The following steps are involved: S1 Preparation of vinyl chlorosulfate: first dissolving vinyl sulfate in an organic solvent, heating to a temperature of 50-120°C, then introducing chlorine gas, and reacting under the catalysis of ultraviolet light to obtain vinyl chlorosulfate; S2 Preparation of erythritol sulfate: Under the action of a metal catalyst, the chlorosulfate prepared in S1 undergoes a dechlorination coupling reaction to prepare erythritol sulfate, and the metal catalyst is selected from any one of copper powder, zinc powder, iron powder, and magnesium powder.

2. The method for preparing erythritol sulfate according to claim 1, characterized in that: The organic solvent described in S1 is selected from any one of chloroform and carbon tetrachloride, the mass of the organic solvent is 5 to 20 times the mass of vinyl sulfate, and the molar ratio of chlorine gas to vinyl sulfate is 1.0 to 1.5:

1.

3. The method for preparing erythritol sulfate according to claim 1, characterized in that: The wavelength of the ultraviolet light described in S1 is 250~400 nm.

4. The method for preparing erythritol sulfate according to claim 1, characterized in that: The molar ratio of the metal catalyst to vinyl chlorosulfate described in S2 is 0.5~4:

1.

5. The method for preparing erythritol sulfate according to claim 1, characterized in that: The reaction temperature of the dechlorination coupling reaction described in S2 is 50~120℃.

6. The method for preparing erythritol sulfate according to claim 1, characterized in that: The dechlorination coupling reaction described in S2 uses at least one of tetrahydrofuran, acetone, cyclohexane, benzene, toluene and xylene as a reaction solvent.

7. The method for preparing erythritol sulfate according to claim 1, characterized in that: After the dechlorination coupling reaction in S2 is completed, a reaction mixture is obtained, and the reaction mixture is subjected to desolvation, water washing, recrystallization, and drying treatments to obtain purified erythritol sulfate.

8. The method for preparing erythritol sulfate according to claim 7, characterized in that: The recrystallization uses at least one of petroleum ether, dichloromethane, n-hexane, methyl acetate, ethyl acetate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate as the recrystallization solvent.

9. The method for preparing erythritol sulfate according to claim 1, characterized in that: The following steps are involved: S1: preparing vinyl chlorosulfate: first dissolving vinyl sulfate in an organic solvent, heating to a temperature of 50-100°C, then introducing chlorine gas, and reacting under the catalysis of ultraviolet light with a wavelength of 250-400 nm to obtain vinyl chlorosulfate, wherein the organic solvent is chloroform or carbon tetrachloride, the mass of the organic solvent is 5-20 times the mass of vinyl sulfate, and the molar ratio of chlorine gas to vinyl sulfate is 1.0-1.5:1; S2 Preparation of erythritol sulfate: Under the action of a metal catalyst, the chlorosulfate prepared in S1 undergoes a dechlorination coupling reaction at 50-120°C. After the reaction is completed, a reaction mixture is obtained, which is subjected to desolvation, water washing, recrystallization, and drying treatments to obtain purified erythritol sulfate. The metal catalyst is selected from any one of copper powder, zinc powder, iron powder, and magnesium powder.

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