Method for producing alkanedisulfonic acid compound

Abstract

The present invention provides an industrially advantageous method for producing an alkanedisulfonic acid compound, said method being capable of easily producing an alkanedisulfonic acid compound with a high yield at a low cost.　The present invention is a method for producing an alkanedisulfonic acid compound, said method comprising a step wherein an alkanedisulfonic acid compound is obtained by reacting at least one alkanesulfonic acid compound having a specific structure with sulfur trioxide in the presence of at least one compound that is selected from the group consisting of sulfone compounds and sulfoxide compounds having a specific structure.

Description

[Technical field]

[0001] The present invention relates to a method for producing an alkanedisulfonic acid compound. [Background technology]

[0002] It has been known that alkanedisulfonic acid compounds are useful not only as pharmaceuticals such as leukemia treatment drugs for animals, but also as raw materials for functional materials such as stabilizers for electrolytes for secondary batteries, and thus they can be said to be highly valuable compounds. It is known that such alkanedisulfonic acid compounds can be produced by various methods.

[0003] For example, Patent Document 1 discloses a method for obtaining a methane disulfonic acid compound, in which methane and sulfur trioxide are treated with mercuric sulfate under an atmosphere of 5.8 MPa and 260° C. for 1.5 hours. Patent Document 2 discloses a method for obtaining methane disulfonic acid by reacting methanesulfonic acid with sulfur trioxide. Patent Document 3 discloses a method for obtaining methane disulfonic acid by reacting dibromomethane with a sulfite in the presence of tetrabutylammonium bromide and potassium iodide to obtain a methanesulfonate salt, and then obtaining methane disulfonic acid using an ion exchange resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 2493038 [Patent Document 2] U.S. Patent No. 2842589 [Patent Document 3] US Patent Application Publication No. 2006 / 0155142 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method disclosed in Patent Document 1 requires the use of a toxic mercury compound and reaction conditions such as high temperature and high pressure, and is not necessarily suitable for industrial production. The method disclosed in Patent Document 2 has a problem that the yield of methane disulfonic acid is low, which is disadvantageous for industrial production. Furthermore, the method disclosed in Patent Document 3 allows the reaction under atmospheric pressure, but the process is complicated, the catalyst remains as an impurity, and a large amount of ion exchange resin is required, making it difficult to carry out on an industrial scale.

[0006] The present invention has been made in view of the above, and an object of the present invention is to provide an industrially advantageous method for producing an alkanedisulfonic acid compound, which can produce an alkanedisulfonic acid compound in high yield, easily and inexpensively. [Means for solving the problem]

[0007] As a result of intensive research into achieving the above-mentioned object, the inventors have discovered that the above-mentioned object can be achieved by reacting a specific alkanesulfonic acid compound with sulfur trioxide in the presence of a specific sulfoxide compound and / or sulfone compound, and have thus completed the present invention.

[0008] That is, the present invention includes, for example, the subject matter described in the following sections. Item 1 A method for producing an alkanedisulfonic acid compound, comprising the steps of: At least one alkane sulfonic acid compound and sulfur trioxide, The method includes a step of obtaining an alkane disulfonic acid compound by reacting in the presence of at least one compound selected from the group consisting of a sulfoxide compound and a sulfone compound, The alkanesulfonic acid compound is represented by the following general formula (1):

[0009] [ka]

[0010] (In formula (1), R 1 and R 2 are the same or different and each represents an alkyl group having 1 to 4 carbon atoms which may be substituted by a halogen atom or a hydrogen atom; n represents an integer of 1 to 4; when n is an integer of 2 to 4, n R 1 may be the same or different, and n R 2 may be the same or different.) A compound represented by the formula: The sulfoxide compound is represented by the following general formula (2):

[0011] [ka]

[0012] (In formula (2), R 3 and R 4 are the same or different and each represents an alkyl group having 1 to 12 carbon atoms which may have a substituent, R 3 and R 4 may be bonded to each other together with the sulfur atom to which they are bonded, with or without a heteroatom to form a cyclic structure. A compound represented by the formula: The sulfone compound is represented by the following general formula (3):

[0013] [ka]

[0014] (In formula (3), R 3 and R 4 are the same or different and each represents an alkyl group having 1 to 12 carbon atoms which may have a substituent, R 3 and R 4 may be bonded to each other together with the sulfur atom to which they are bonded, with or without a heteroatom to form a cyclic structure. A compound represented by the formula: The alkane disulfonic acid compound is represented by the following general formula (4):

[0015] [ka]

[0016] (In formula (4), R 1 , R 2 and n are each R in formula (1). 1 , R 2 and n.) A method for producing an alkanedisulfonic acid compound represented by the formula: Section 2 Item 2. The method according to Item 1, wherein the sulfoxide compound is dimethyl sulfoxide. Section 3 Item 3. The method according to item 1 or 2, wherein the sulfone compound is at least one selected from the group consisting of sulfolane, 3-methylsulfolane, ethyl methyl sulfone, and ethyl isopropyl sulfone. Effect of the Invention

[0017] According to the production method of the present invention, it is possible to produce an alkanedisulfonic acid compound in high yield, easily and inexpensively, and is industrially advantageous. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described in detail. In this specification, the term "comprising" includes "consisting essentially of" and "consisting of."

[0019] In the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example or a value that can be unambiguously derived from an example. In addition, in this specification, a numerical value connected with "~" means a numerical range that includes the numerical values ​​before and after "~" as the lower and upper limits.

[0020] The method for producing an alkanedisulfonic acid compound of the present invention includes a step of reacting at least one alkanedisulfonic acid compound with sulfur trioxide in the presence of at least one compound selected from the group consisting of a sulfoxide compound and a sulfone compound to obtain an alkanedisulfonic acid compound, which will hereinafter be referred to as "Step A."

[0021] (Alkanesulfonic acid compounds) The alkanesulfonic acid compound used in step A is a compound represented by the following general formula (1).

[0022] [ka]

[0023] Here, in formula (1), R 1 and R 2 are the same or different and each represents an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom or a hydrogen atom, and n represents an integer of 1 to 4. In formula (1), when n is an integer of 2 to 4, n R 1 may be the same or different. When n is an integer of 2 to 4, n R 2 may be the same or different.

[0024] R in Equation (1) 1 and R 2In the above, the type of the alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom is not particularly limited. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Specific examples of the alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a fluoromethyl group, a trifluoromethyl group, a chloromethyl group, a chloroethyl group, a chloropropyl group, and a bromomethyl group.

[0025] In formula (1), R 1 R is preferably a hydrogen atom, a methyl group, an ethyl group, or an n-propyl group, and more preferably a hydrogen atom. 2 is preferably a hydrogen atom, a methyl group, an ethyl group, or an n-propyl group, and more preferably a hydrogen atom. 1 and R 2 are preferably the same.

[0026] In formula (1), when n is an integer of 2 to 4, that is, when n is 2, 3, or 4, n R 1 may be the same or different, and similarly, n R 2 In formula (1), when n is an integer of 2 to 4, n R 1 are preferably all the same, and when n is an integer of 2 to 4, n R 2 are preferably all the same.

[0027] In the formula (1), n ​​is particularly preferably 1, in which case the yield of the target alkanedisulfonic acid compound tends to be particularly high.

[0028] The alkane sulfonic acid compound is not particularly limited as long as it is a compound represented by formula (1). Preferably, the alkane sulfonic acid compound is methanesulfonic acid (in formula (1), R 1 =R 2=H, n=1), ethanesulfonic acid (in formula (1), R 1 =CH3, R 2 =H, n=1), 1-propanesulfonic acid (in formula (1), R 1 =CH2CH3,R 2 =H, n=1), 2-propanesulfonic acid (in formula (1), R 1 =R 2 =CH3, n=1), 1-butanesulfonic acid (in formula (1), R 1 =R 2 =H, n=4), etc.

[0029] The alkane sulfonic acid compound used in step A can be obtained from a commercial product, or can be obtained by a known method or a method easily derived from a known method. For example, the alkane sulfonic acid compound can be synthesized by a method of oxidizing a corresponding disulfide compound using methyltrioxorhenium(VII) / hydrogen peroxide as a catalyst, with reference to Tetrahedron Letters (2009), 50(46), 6231-6232. Alternatively, the alkane sulfonic acid compound can be synthesized by a method of oxidizing a corresponding thiol compound using hydrogen peroxide, with reference to International Publication No. WO 2004 / 058693.

[0030] The alkanesulfonic acid compound used in step A may be one type alone or two or more types in combination.

[0031] (Sulfoxide compounds and sulfone compounds) In step A, either or both of a sulfoxide compound and a sulfone compound can be used.

[0032] The sulfoxide compound is a compound represented by the following general formula (2).

[0033] [ka]

[0034] Here, in formula (2), R 3 and R 4 are the same or different and each represents an alkyl group having 1 to 12 carbon atoms which may have a substituent. In formula (2), R 3 and R 4 may be bonded to each other together with the sulfur atom to which they are attached to form a cyclic structure with or without a heteroatom.

[0035] The sulfone compound is a compound represented by the following general formula (3).

[0036] [ka]

[0037] Here, in formula (3), R 3 and R 4 are the same or different and each represents an alkyl group having 1 to 12 carbon atoms which may have a substituent, R 3 and R 4 may be bonded to each other together with the sulfur atom to which they are bonded, with or without a heteroatom to form a ring structure. 3 and R 4 is R in Eq. (2). 3 and R 4 is synonymous with.

[0038] R in formula (2) and formula (3) 3 and R 4 In the formula (I), when the alkyl group having 1 to 12 carbon atoms has a substituent, the type of the substituent is not particularly limited. Specific examples of the substituent include a halogen atom, an alkoxy group, a carboxyl group, a cyano group, a nitro group, and a sulfo group.

[0039] R in formula (2) and formula (3) 3 and R 4In the above, examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, an n-decyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, and a 2-cyclohexylethyl group. These alkyl groups may also have the above-mentioned substituent. The number of carbon atoms is preferably 1 to 6, in that the yield of the target alkanedisulfonic acid compound is likely to be high. Therefore, among the above-listed examples of the alkyl group having 1 to 12 carbon atoms, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, or a cyclopentylmethyl group is preferred.

[0040] In formula (2) and formula (3), R 3 and R 4 and may be bonded together with the sulfur atom to which they are bonded to form a cyclic structure with or without a heteroatom. That is, they may form a cyclic structure containing the sulfur atom in the compounds represented by formulas (2) and (3) as a ring member. In this case, for example, R 3 and R 4 The carbon atoms of R can form chemical bonds to form a ring structure. For example, R 3 and R 4 A cyclic structure can be formed together with the sulfur atom by a covalent bond between the terminal carbon atoms of the ring. The cyclic structure is, for example, a saturated ring containing a sulfur atom. When the cyclic structure has a hetero atom in addition to the sulfur atom, the type of the hetero atom is not particularly limited.

[0041] In the step A, when both the compound represented by formula (2) and the compound represented by formula (3) are used, R 3 and R in Eq. (3) 3may be the same or different. Similarly, in the case where both the compound represented by formula (2) and the compound represented by formula (3) are used in step A, R 4 and R in Eq. (3) 4 may be the same or different from each other.

[0042] Specific examples of the sulfoxide compound represented by formula (2) include dimethyl sulfoxide, ethyl methyl sulfoxide, methyl n-propyl sulfoxide, dipropyl sulfoxide, dibutyl sulfoxide, di-n-octyl sulfoxide, didodecyl sulfoxide, and tetramethylene sulfoxide. Among these, the sulfoxide compound represented by formula (2) is preferably dimethyl sulfoxide.

[0043] Specific examples of the sulfone compound represented by formula (3) include trimethylene sulfone, hexamethylene sulfone, trimethylene disulfone, tetramethylene disulfone, hexamethylene disulfone, sulfolane, 3-methyl sulfolane, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, methyl n-propyl sulfone, ethyl n-propyl sulfone, di-n-propyl sulfone, methyl isopropyl sulfone, ethyl isopropyl sulfone, diisopropyl sulfone, n-butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, etc. Among these, the sulfone compound represented by formula (3) is preferably sulfolane, 3-methyl sulfolane, ethyl methyl sulfone, or ethyl isopropyl sulfone, more preferably sulfolane or 3-methyl sulfolane, and even more preferably sulfolane.

[0044] In the case where both the compound represented by formula (2) and the compound represented by formula (3) are used in step A, the sulfoxide compound and the sulfone compound are preferably at least one selected from the group consisting of dimethyl sulfoxide, sulfolane, 3-methyl sulfolane, ethyl methyl sulfone, and ethyl isopropyl sulfone, more preferably at least one selected from the group consisting of sulfolane, 3-methyl sulfolane, ethyl methyl sulfone, and ethyl isopropyl sulfone, and particularly preferably contain at least sulfolane.

[0045] In step A, the sulfoxide compound and the sulfone compound may be used alone or in combination of two or more kinds.

[0046] The sulfoxide compound and the sulfone compound used in step A are both commercially available, or can be obtained by adopting a known production method or the like.

[0047] (Reaction in Step A) In step A, at least one alkanesulfonic acid compound is reacted with sulfur trioxide (SO3) in the presence of at least one compound selected from the group consisting of sulfoxide compounds and sulfone compounds.

[0048] The total amount of the sulfoxide compound and the sulfone compound used in the reaction of step A is preferably 0.1 mol or more, more preferably 0.2 mol or more, and even more preferably 0.3 mol or more, relative to 1 mol of sulfur trioxide, in that the yield of the target alkanedisulfonic acid compound is likely to be high. Moreover, the total amount of the sulfoxide compound and the sulfone compound used in the reaction of step A is preferably 10 mol or less, more preferably 8 mol or less, and even more preferably 6 mol or less, relative to 1 mol of sulfur trioxide, in that it is more economical.

[0049] The amount of sulfur trioxide used in the reaction of step A is preferably 0.1 mol or more, more preferably 0.2 mol or more, and even more preferably 0.3 mol or more, relative to 1 mol of the alkane sulfonic acid compound, in that the yield of the target alkane disulfonic acid compound is likely to be high. Moreover, the amount of sulfur trioxide used in the reaction of step A is preferably 10 mol or less, more preferably 8 mol or less, and even more preferably 6 mol or less, relative to 1 mol of the alkane sulfonic acid compound, in that it is more economical. Here, "1 mol of the alkane sulfonic acid compound" means that when two or more kinds of alkane sulfonic acid compounds are used, the total amount of them is 1 mol.

[0050] In the reaction of step A, for example, a raw material A containing the alkane sulfonic acid compound, sulfur trioxide, and at least one selected from the group consisting of the sulfoxide compound and the sulfone compound is placed in a reaction vessel, and the reaction can be carried out in the reaction vessel. In this case, the raw material A can also be dissolved or dispersed in a solvent as necessary. When a solvent is used, the amount of the solvent used is not particularly limited, and can be, for example, 1500 parts by mass or less, and preferably 1000 parts by mass or less, relative to 100 parts by mass of the total amount of the alkane sulfonic acid compound.

[0051] When the raw material A is dissolved or dispersed in a solvent, the solvent that can be used can be appropriately selected within a range that does not impair the effects of the present invention. Examples of such solvents include hydrocarbon solvents, halogen solvents, ether solvents, ketone solvents, ester solvents, amide solvents, nitrile solvents, and sulfuric acid. Examples of hydrocarbon solvents include toluene, xylene, monochlorobenzene, dichlorobenzene, trichlorobenzene, hexane, heptane, and decane. Examples of halogen solvents include dichloromethane and 1,2-dichloroethane. Examples of ether solvents include diethyl ether, ethylene glycol dimethyl ether, diisopropyl ether, diphenyl ether, tetrahydrofuran, dioxane, methyl-tert-butyl ether, and cyclopentyl methyl ether. Examples of ketone solvents include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of ester solvents include ethyl acetate and butyl acetate. Examples of amide solvents include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. An example of the nitrile solvent is acetonitrile.

[0052] The raw material A used in the step A may contain other additives in addition to the solvent, or may consist of only at least one compound selected from the group consisting of the alkane sulfonic acid compound, sulfur trioxide (SO), sulfoxide compounds, and sulfone compounds.

[0053] The type of reaction vessel used in the reaction of step A is not particularly limited, and for example, a wide variety of known reaction vessels can be used.

[0054] The reaction conditions in step A are not particularly limited. For example, the reaction temperature in step A is not particularly limited and can be appropriately set depending on the conditions such as the type of raw material and the amount of raw material. For example, the reaction temperature can be 0 to 200°C, and is preferably 50 to 180°C, more preferably 80 to 170°C, and even more preferably 100 to 160°C, in that the yield of the target product is likely to be high. The reaction time can be appropriately set depending on the reaction temperature, and can be, for example, about 1 to 48 hours.

[0055] In the reaction of step A, the method for adjusting the reaction temperature is not particularly limited. For example, the reaction temperature can be set to an appropriate temperature by heating the reaction vessel in which the raw material A is placed.

[0056] The reaction can be carried out while stirring the raw material A with a stirrer or the like. The reaction can also be carried out by charging all the raw materials in a reaction vessel in random order and maintaining the temperature at a predetermined level. Alternatively, the reaction can be carried out while adding any one or more raw materials dropwise.

[0057] The reaction in step A can be carried out under any of increased pressure, reduced pressure, and atmospheric pressure. The reaction in step A can also be carried out in an inert gas atmosphere such as nitrogen or argon. The reaction can also be carried out while blowing in an inert gas.

[0058] The target alkane disulfonic acid compound is produced by the reaction in step A. This alkane disulfonic acid compound is a compound represented by the following general formula (4).

[0059] [ka]

[0060] Here, in formula (4), R 1 , R 2 and n are each R in formula (1). 1 , R 2 and n.

[0061] Specific examples of the alkane disulfonic acid compound represented by formula (4) include methane disulfonic acid (R 1 =R 2 =H, n=1), ethanedisulfonic acid (R 1 =CH3, R 2 =H, n=1), 1-propanedisulfonic acid (R 1 =CH2CH3,R 2 =H, n=1), 2-propanedisulfonic acid (R 1 =R 2 =CH3, n=1), 1-butanedisulfonic acid (R 1 =R 2 =H, n=4) and the like.

[0062] The alkane disulfonic acid compound obtained in step A can be isolated by a conventionally known purification operation and isolation operation, and the method is not particularly limited. For example, the alkane disulfonic acid compound obtained in step A can be isolated by a method such as extracting the reaction liquid obtained after the reaction in step A using a solvent, washing, and then crystallizing. When the obtained alkane disulfonic acid compound is used as a raw material for another reaction, it is not necessarily necessary to isolate it, and the reaction liquid containing the alkane disulfonic acid compound can be directly used in the subsequent reaction. For example, the alkane disulfonic acid compound obtained in step A can be used as a raw material for producing a methylene disulfonate compound.

[0063] Usually, in the production of an alkanedisulfonic acid compound using sulfur trioxide, the reaction between sulfur trioxide and the alkanedisulfonic acid compound is difficult to occur, and the yield of the alkanedisulfonic acid compound is low. In contrast, when the reaction is carried out in the presence of at least one compound selected from the group consisting of sulfoxide compounds and sulfone compounds, as in step A, these compounds have the effect of effectively reacting sulfur trioxide with the alkanesulfonic acid compound, making the reaction between sulfur trioxide and the alkanesulfonic acid compound more likely to occur, and improving the yield of the produced alkanedisulfonic acid compound.

[0064] The present disclosure includes all arbitrary combinations of the constituent features described in this specification. In addition, the various characteristics (properties, structures, functions, etc.) described for each embodiment of the present disclosure above may be combined in any way to specify the subject matter included in the present disclosure. In other words, the present disclosure includes all subject matter consisting of all combinations of each combinable characteristic described in this specification. EXAMPLES

[0065] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the embodiments of these examples.

[0066] Example 1 A four-neck flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel was charged with 19.2 g (0.20 mol) of methanesulfonic acid, 20.0 g (0.17 mol) of sulfolane, and 16.0 g (0.20 mol) of sulfur trioxide as raw material A. The temperature of raw material A in the flask was raised to 150°C while stirring, and the reaction was continued at this temperature for 5 hours to obtain a reaction liquid. An appropriate amount of the reaction liquid obtained was sampled and analyzed by ion chromatography, and based on the area value of the peak obtained in this analysis, the product methanedisulfonic acid (R 1 and R 2 The production yield of the compound (wherein n is a hydrogen atom and n is 1) was calculated. As a result, the production yield of the obtained methanedisulfonic acid was 74 mol %.

[0067] Example 2 In the preparation of raw material A, methane disulfonic acid (R 1 and R 2 A compound in which n is a hydrogen atom and n is 1 was produced, and the production yield was calculated. As a result, the production yield of the obtained methanedisulfonic acid was 77 mol %.

[0068] Example 3 In the preparation of raw material A, the same procedure as in Example 1 was used to prepare methane disulfonic acid (R 1 and R 2 A compound in which n is a hydrogen atom and n is 1 was produced, and the production yield was calculated. As a result, the production yield of the obtained methanedisulfonic acid was 83 mol %.

[0069] Comparative Example 1 In the preparation of raw material A, methane disulfonic acid (R 1 and R 2 A compound in which n is a hydrogen atom and n is 1 was produced, and the production yield was calculated. As a result, the production yield of the obtained methanedisulfonic acid was 40 mol %.

[0070] From the above results, it was found that the production methods performed in the respective Examples can smoothly proceed with the reaction by including step A, and can obtain the target product, methanedisulfonic acid, represented by formula (4), in high production yield. That is, it was demonstrated that the production method according to the present invention can easily and inexpensively produce an alkanedisulfonic acid compound in high yield, and is industrially advantageous.

Claims

1. A method for producing an alkanedisulfonic acid compound, comprising the steps of: At least one alkane sulfonic acid compound and sulfur trioxide, a step of obtaining an alkane disulfonic acid compound by reacting in the presence of a sulfone compound, The alkanesulfonic acid compound is represented by the following general formula (1): 【Chemistry 1】 (In formula (1), R １ and R ２ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms which may be substituted by a halogen atom or a hydrogen atom; n represents an integer of 1 to 4; when n is an integer of 2 to 4, n R １ may be the same or different, and n R ２ may be the same or different.) A compound represented by the formula: The sulfone compound is represented by the following general formula (3): 【Chemistry 2】 (In formula (3), R ３ and R ４ are the same or different and each represents an alkyl group having 1 to 6 carbon atoms which may have a substituent; R ３ and R ４ may be bonded to each other together with the sulfur atom to which they are bonded, with or without a heteroatom to form a cyclic structure. A compound represented by the formula: The alkanedisulfonic acid compound is represented by the following general formula (4): 【Chemistry 4】 (In formula (4), R １ , R ２ and n are each R in formula (1). １ , R ２ and n.) The present invention relates to a method for producing an alkanedisulfonic acid compound represented by the following formula:

2. The method according to claim 1, wherein the sulfone compound is at least one selected from the group consisting of sulfolane, 3-methylsulfolane, ethyl methyl sulfone, and ethyl isopropyl sulfone.

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