Preparation method of high-purity methyldisulfonic acid

Abstract

The invention belongs to the field of organic synthesis, provides a preparation method of high-purity methyldisulfonic acid, and solves the problems of low purity, high water content, high metal ion content and poor product quality of methyldisulfonic acid in the prior art. The preparation method comprises the following steps: S1, reacting a methyldisulfonic acid crude product with a trialkylsilyl compound, timely removing reaction byproducts in the reaction process, and after the reaction is finished, carrying out reduced pressure rectification to obtain methyldisulfonic acid bis-silyl ester; and S2, reacting the methyldisulfonic acid disilyl ester with water and / or alcohol to generate methyldisulfonic acid, and after the reaction is finished, separating and purifying a product to obtain a high-purity methyldisulfonic acid product. According to the technical scheme, the problems existing in the prior art are well solved, and the method can be applied to the downstream application fields, such as lithium batteries, semiconductors and the like, which have high requirements on the quality of methyldisulfonic acid products.

Description

Technical Field

[0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing high-purity methanedisulfonic acid. Background Art

[0002] Methanedisulfonic acid, also known as methylenedisulfonic acid, is widely used in chemical synthesis, electroplating and other industrial fields. With the rise of the lithium battery industry, methanedisulfonic acid is often used as an intermediate for synthesizing methylene disulfonate, a lithium battery additive. In addition, methanedisulfonic acid can also be directly applied to lithium battery materials and semiconductor industries. For example, CN103755147A discloses an ITO film etching solution with methanedisulfonic acid as the main component. The application in these fields places high demands on the purity of methanedisulfonic acid, especially the impurity content, such as moisture, metal ions, etc.

[0003] Regarding the preparation method of methyl disulfonic acid, one is to use methanesulfonic acid and sulfur trioxide to react, such as US2842589A. The methyl disulfonic acid obtained by this method contains more impurity acids such as methanesulfonic acid and sulfuric acid, which is difficult to separate and purify; CN115052858A, CN115066415A and others have improved it, using cyclopentane as a solvent or directly using cyclopentane-sulfur trioxide complex as a sulfonation reagent during the sulfonation process, which improves the yield of methyl disulfonic acid, but still does not solve the problem of purification; CN116693427A proposes to crystallize methyl disulfonic acid from the reaction mixture by cooling after the reaction to purify the product, but this method has high equipment requirements and complex process operations, and it is difficult to achieve industrialization. Another mainstream route is to use dichloromethane and sulfite solution for sulfonation reaction, and then prepare it through acidification. The sulfonation process of this route requires high temperature and high pressure to achieve, and the product contains a large amount of Na + , Ca 2+ Mg 2+ , K + , Fe 2+ etc. metal ions, among which Na + The content of impurities can be as high as 3000ppm or more, which is difficult to remove, and more impurity acids remain during acidification, and the purity of the product methyl disulfonic acid is only about 96%; CN108516944B uses dibromomethane and a phase transfer catalyst to improve the process and obtain a crude methyl disulfonic acid, but the purity and water content are not improved; CN109422670B discloses a method for preparing a low-moisture and high-purity alkyl disulfonic acid, after preliminary decompression distillation to remove water, methyl orthosilicate is added to react and remove crystal water to obtain a low-moisture finished product, but this method does not solve the problem of purifying methyl disulfonic acid and removing metal ions. Summary of the invention

[0004] The invention aims to solve the problems of low product purity, high water content and metal ion content and poor product quality in the existing methane disulfonic acid preparation process, and to provide a method for preparing high-purity methane disulfonic acid. The method has the advantages that the prepared methane disulfonic acid product has high purity, low water content, low metal ion content and good product quality.

[0005] In order to achieve the above technical purpose, the technical solution adopted by the present invention is: to provide a method for preparing high-purity methanedisulfonic acid, comprising the following steps:

[0006] S1: reacting crude methyl disulfonic acid with a trialkylsilyl compound, removing the reaction by-products in time during the reaction, and performing vacuum distillation after the reaction to obtain methyl disulfonic acid disilyl ester;

[0007] S2: Disilyl methyl disulfonate reacts with water and / or alcohol to generate methyl disulfonic acid. After the reaction is completed, the product is separated and purified to obtain a high-purity methyl disulfonic acid product.

[0008] Furthermore, the trialkylsilyl compound described in step S1 is selected from at least one of hexaalkyldisiloxane, hexaalkyldisilazane, hexaalkyldisilurea, heptaalkyldisilazane, trialkylchlorosilane, trialkyloxysilane, trialkylacyloxysilane, trialkylsilylamine, trialkylsilylimidazole, trialkylamineoxysilane, trialkylalkenyloxysilane, trialkyloximesilane or N,O-bistrialkylsilylacetamide.

[0009] Furthermore, the trihydrocarbyl silicon-based compound described in step S1 is selected from at least one of hexamethyldisiloxane, trimethylchlorosilane, hexamethyldisilazane, heptamethyldisilazane, trimethylmethoxysilane, trimethylethoxysilane, trimethylsilylimidazole, hexamethyldisilurea or N,O-bistrimethylsilylacetamide.

[0010] Furthermore, the reaction temperature of step S1 is 20-150° C., the reaction time is 4-60 h, the molar ratio of the silicon element of the trialkylsilyl compound to the sulfonic acid group in methyl disulfonic acid is 0.5-10:1, and the pressure of the vacuum distillation is 0.01-10 kPa.

[0011] Furthermore, the reaction temperature of step S1 is 40-110° C., the reaction time is 8-48 hours, and the molar ratio of the silicon element in the trialkylsilyl compound to the sulfonic acid group in methyl disulfonic acid is 1-5:1.

[0012] Furthermore, in step S2, the reaction temperature is -10 to 100° C., the reaction time is 4 to 48 hours, and the molar ratio of water or alcohol to disiloxane dimethyl disulfonate is not less than 1.

[0013] Furthermore, in step S2, the reaction temperature is 25-60° C., the reaction time is 8-24 hours, and the molar ratio of water or alcohol to disiloxane methyl disulfonate is 1-4:1.

[0014] Furthermore, in step S2, a reaction solvent is used to promote dispersion, and the reaction solvent is selected from at least one of hydrocarbons, halogenated hydrocarbons, esters, ethers, ketones, nitriles, amides or sulfone solvents.

[0015] Furthermore, the reaction solvent described in step S2 is selected from at least one of toluene, cyclohexane, cyclopentane, dichloromethane, dichloroethane, chloroform, ethyl formate, ethyl acetate, propyl acetate, dimethyl carbonate, diethyl carbonate, ether, 1,3-dioxolane, 1,4-dioxane, acetone, acetonitrile, dimethylformamide or dimethyl sulfoxide.

[0016] Furthermore, in the step S2, after the reaction is completed, the solvent and silicon-containing by-products are first recovered by reduced pressure distillation, and then residual low-boiling substances and / or water are removed by high vacuum drying to obtain a high-purity methanedisulfonic acid product with a product purity of ≥99%, and the individual content of metal ions (Al, Ca, Fe, K, Mg, Na, Zn, Cr, Cu, Pb) does not exceed 10 ppm.

[0017] The beneficial effects of the present invention are:

[0018] The invention provides a method for preparing high-purity methyl disulfonic acid through a large number of experimental studies. The method comprises the following steps: a crude methyl disulfonic acid product is reacted with a trialkylsilyl compound and distilled to obtain a transitional intermediate product, disilyl methyl disulfonate. The disilyl ester is hydrolyzed or alcoholyzed to obtain methyl disulfonic acid. The silicon-containing byproduct can be recycled and reused, and the raw material utilization rate is high. The obtained methyl disulfonic acid product has good quality and can meet the downstream application requirements of lithium batteries, semiconductors and the like that have high requirements on the quality of methyl disulfonic acid products.

[0019] Therefore, the preparation method of high-purity methanedisulfonic acid provided by the present invention has the advantages of high product yield, high purity, low moisture content, low metal ion content, green environmental protection, and low production cost, and achieves good technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the H NMR spectrum of bis(trimethylsilyl)methyl disulfonate in Example 1.

[0021] Figure 2 This is the H NMR spectrum of high-purity methanedisulfonic acid in Example 1. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further explained below in conjunction with specific implementation methods, but the following embodiments are only examples for explaining the present application and are not limitations on the content of the present application. Under the guidance of this specification, those skilled in the art may make improvements or modifications to the content of the present invention without creative contribution as needed, which all fall within the protection scope of the present invention.

[0023] Reaction temperature, unless otherwise specified, generally refers to the internal temperature of the reaction materials.

[0024] Reaction pressure, unless otherwise specified, generally refers to absolute pressure.

[0025] The purity of methanedisulfonic acid was checked by ion chromatography (IC).

[0026] The metal ion content was detected by inductively coupled plasma optical emission spectrometry (ICP).

[0027] The yield is the percentage ratio of the actual product mass to the theoretical product mass, where the theoretical product mass is calculated based on the non-excess raw materials in the reaction equation.

[0028] The present application is further described in detail below in conjunction with embodiments.

[0029] [Example 1]

[0030] A method for preparing high-purity methanedisulfonic acid comprises the following steps:

[0031] S1: In a 3L reaction bottle equipped with nitrogen protection, magnetic stirring, thermometer, reflux condenser, and tail gas absorption device, 733.6g of commercially available methanedisulfonic acid product (content 96%, water content 0.18%, Na + Content 3025ppm, Ca 2+ Content 178ppm, Mg 2+ Content 11.1ppm, K + Content 11.2ppm, Fe 2+ The content was 7.65ppm), hexamethyldisilazane 1936.8g, heated to 105-110℃ for 30h, and the by-product ammonia was absorbed in time during the reaction; the water pump was used for vacuum distillation, and the excess hexamethyldisilazane was recovered at 3.3-4.5kPa; the rotary vane pump was switched for vacuum distillation, and the 118-120℃ / 0.13kPa fraction was collected to obtain 1161.6g of colorless transparent liquid, namely bistrimethylsilyl dimethylsulfonate, and the results of H NMR spectrum determination were 1 H-NMR (400MHz, DMSO-d6) δ (ppm): 4.14 (-CH2-), 0.36 (-Si(CH3)3).

[0032]

[0033] S2: In a 1L reaction bottle equipped with a magnetic stirrer, a thermometer, and a reflux condenser, 144.8g of bis(trimethylsilyl)methyl disulfonate and 500mL of dichloroethane were added, and 43.2g of methanol was added dropwise at room temperature. The temperature was raised to 50-55°C for 12h, and the solvent and the by-product trimethylmethoxysilane were recovered by vacuum distillation with a water pump; the rotary vane pump was switched and dried on a rotary evaporator at 75-80°C / 0.3kPa for 24h to obtain 76.1g of white crystals, which were the methyl disulfonic acid product, with a yield of 95.2%, a purity of 99.6%, and a moisture content of 157ppm. The metal ion content test results (Al, Ca, Fe, K, Mg, Na, Zn, Cr, Cu, Pb) were as follows: Na + Content 7.2ppm, Mg 2+ Content 1.3ppm, Ca 2+ The content is 6.7ppm, and the rest is <1ppm; the results of nuclear magnetic hydrogen spectrum are 1 H-NMR (400MHz, DMSO-d6) δ (ppm): 3.82 (-CH2-), 11.09 (-SO3H).

[0034]

[0035] [Example 2]

[0036] A method for preparing high-purity methanedisulfonic acid comprises the following steps:

[0037] S1: In a 5L reaction bottle equipped with nitrogen protection, magnetic stirring, thermometer, water separator, and reflux condenser, 1184.8g of methyl disulfonic acid product prepared by sulfur trioxide process (purity 59.5%, methanesulfonic acid content 1.1%, sulfuric acid content 18.3%, other impurities content 21.0%, Na + Content 35.0ppm, Ca 2+ Content 78.0ppm, Mg 2+ Content 8.1ppm, K + Content 7.2ppm, Fe 2+ Content 75.6ppm), hexamethyldisiloxane 2593.6g, heating temperature, 96 ~ 110 ℃ reaction water separation 26h, water pump vacuum distillation, 3.3 ~ 4.5kPa recovery of excess hexamethyldisiloxane; switch rotary vane pump, vacuum distillation, collect 118 ~ 120 ℃ / 0.13kPa fraction, 1007.2g colorless transparent liquid, that is, methyl disulfonic acid bistrimethylsilyl ester, nuclear magnetic hydrogen spectrum determination results are 1 H-NMR (400MHz, DMSO-d6) δ (ppm): 4.14 (-CH2-), 0.36 (-Si(CH3)3).

[0038]

[0039] S2: In a 500mL reaction bottle equipped with a magnetic stirrer, a thermometer, and a reflux condenser, 125.4g of bistrimethylsilyl methanesulfonate and 200mL of dichloromethane were added, and 8.5g of pure water was added dropwise at room temperature. The mixture was heated to a temperature of 30-35°C for 16h, and the solvent and the by-product hexamethyldisiloxane were recovered by vacuum distillation with a water pump; a rotary vane pump was switched and the mixture was dried on a rotary evaporator at 75-80°C / 0.3kPa for 24h to obtain 65.4g of white crystals, i.e., methanedisulfonic acid product, with a yield of 94.5%, a purity of 99.6%, a moisture content of 258ppm, and metal ion content test results (Al, Ca, Fe, K, Mg, Na, Zn, Cr, Cu, Pb) were as follows: Na + Content 3.7ppm, Ca 2+ The content is 8.0ppm, and the rest is <1ppm; the results of nuclear magnetic hydrogen spectrum are 1 H-NMR (400MHz, DMSO-d6) δ (ppm): 3.82 (-CH2-), 11.09 (-SO3H).

[0040]

[0041] In summary, the preparation method of high-purity methyl disulfonic acid provided by the present invention comprises the following steps: crude methyl disulfonic acid is reacted with a trialkylsilyl compound, and distilled under reduced pressure to obtain disilyl methyl disulfonate, and high-purity methyl disulfonic acid is obtained after hydrolysis or alcoholysis. The silicon-containing by-product can be reused, and the raw material utilization rate is high. The methyl disulfonic acid obtained has high yield, high purity, low moisture content, and low metal ion content. The process is green and environmentally friendly, and the production cost is low, and the downstream application requirements of lithium batteries, semiconductors, etc., which have high requirements on the quality of methyl disulfonic acid products, can be met.

Claims

1. A method for preparing high-purity methanedisulfonic acid, comprising the following steps: S1: reacting crude methyl disulfonic acid with a trialkylsilyl compound, removing the reaction by-products in time during the reaction, and performing vacuum distillation after the reaction to obtain methyl disulfonic acid disilyl ester; S2: Disilyl methyl disulfonate reacts with water and / or alcohol to generate methyl disulfonic acid. After the reaction is completed, the product is separated and purified to obtain a high-purity methyl disulfonic acid product.

2. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The trialkylsilyl compound described in step S1 is selected from at least one of hexaalkyldisiloxane, hexaalkyldisilazane, hexaalkyldisilurea, heptaalkyldisilazane, trialkylchlorosilane, trialkyloxysilane, trialkylacyloxysilane, trialkylsilylamine, trialkylsilylimidazole, trialkylamineoxysilane, trialkylalkenyloxysilane, trialkyloximesilane or N,O-bistrialkylsilylacetamide.

3. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The trihydrocarbylsilyl compound described in step S1 is selected from at least one of hexamethyldisiloxane, trimethylchlorosilane, hexamethyldisilazane, heptamethyldisilazane, trimethylmethoxysilane, trimethylethoxysilane, trimethylsilylimidazole, hexamethyldisilurea or N,O-bistrimethylsilylacetamide.

4. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The reaction temperature of step S1 is 20 to 150° C., the reaction time is 4 to 60 hours, the molar ratio of the silicon element of the trialkylsilyl compound to the sulfonic acid group in methyl disulfonic acid is 0.5 to 10:1, and the pressure of the vacuum distillation is 0.01 to 10 kPa; the reaction temperature of step S2 is -10 to 100° C., the reaction time is 4 to 48 hours, and the molar ratio of water or alcohol to disiloxane methyl disulfonic acid is not less than 1.

5. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The reaction temperature of step S1 is 40-110°C, the reaction time is 8-48h, and the molar ratio of the silicon element of the trialkylsilyl compound to the sulfonic acid group in methyl disulfonic acid is 1-5:1; the reaction temperature of step S2 is 25-60°C, the reaction time is 8-24h, and the molar ratio of water or alcohol to methyl disulfonic acid disilyl ester is 1-4:

1.

6. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The step S2 uses a reaction solvent to promote dispersion, and the reaction solvent is selected from at least one of hydrocarbons, halogenated hydrocarbons, esters, ethers, ketones, nitriles, amides or sulfone solvents.

7. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: The step S2 uses a reaction solvent to promote dispersion, and the reaction solvent is selected from at least one of toluene, cyclohexane, cyclopentane, dichloromethane, dichloroethane, chloroform, ethyl formate, ethyl acetate, propyl acetate, dimethyl carbonate, diethyl carbonate, ether, 1,3-dioxolane, 1,4-dioxane, acetone, acetonitrile, dimethylformamide or dimethyl sulfoxide.

8. The method for preparing high-purity methanedisulfonic acid according to claim 1, characterized in that: In the step S2, after the reaction is completed, the solvent and silicon-containing by-products are firstly recovered by vacuum distillation, and then the residual low-boiling substances and / or water are removed by vacuum drying to obtain a high-purity methanedisulfonic acid product, the product purity of which is ≥99%, and the individual content of metal ions (Al, Ca, Fe, K, Mg, Na, Zn, Cr, Cu, Pb) does not exceed 10ppm.

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