JP2002275151A - Purification of sulfonic acid compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the easy removal of iodate salts as a reaction by-product in consideration of the difficulty in separation of by-products, namely iodic acid and iodate salts, from the objective compound. SOLUTION: A mixture of sulfonic acid represented by general formula (1) (R<1> SO3 )n M<1> (wherein R<1> is an alkyl, allyl, aryl, perfluoroalkyl; M<1> is H, an organic group, a mono-trivalent metal; n is an integer of 1-3), sulfinic acid of represented by general formula (1) (R<2> SO2 )m M<2> (wherein R<2> is an alkyl, allyl, aryl, perfluoroalkyl; M<2> is H, an organic group, a mono-trivalent metal; m is an integer of 1-3) and iodide compounds represented by general formula (3) M<3> X1 (wherein M<3> is H, ammonium, a mono-trivalent metal; X is iodine and l is an integer of 1-3) is oxidized, followed by removal of iodine whereby the sulfonic acid compound are purified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst for an organic chemical reaction,
The present invention relates to a method for purifying a sulfonic acid compound having an organic group, particularly a perfluoroalkyl group, which can be used as a surfactant or a flame retardant.

[0002]

2. Description of the Related Art Alkyl sulfonic acids having an alkyl group, an allyl group, an aryl group, a perfluoroalkyl group, etc. and their salts are used as various surfactants, flame retardants, and catalysts such as esterification in organic chemical reactions. It is used for Several methods are known for synthesizing this type of sulfonate from readily available halogen compounds. For example, as a method of synthesizing an alkyl sulfonate from a commonly available alkyl halide in one step, [Ann. 148, 90 (1868)]
Stregger's method for synthesizing sulfonic acids, which synthesizes alkyl sulfonates using alkyl halides and sulfites, has been reported. According to this method, by reacting a perfluoroalkyl halide with a sulfite, a perfluoroalkyl sulfonate is produced as a main product, and a halide salt is produced as a by-product. Usually, as a method of purifying the alkyl sulfonate of this mixture, a method of extracting the alkyl sulfonate with a polar organic solvent is used.

However, a highly reactive perfluoroalkyl iodide is usually used as an alkyl halide as a raw material, and sodium iodide as a by-product has high solubility in a polar organic solvent as an extraction solvent. Therefore, a large amount of sodium iodide is contained in the obtained perfluoroalkyl sulfonate, resulting in insufficient purification.

[0004] Also, Japanese Patent Publication No. 62-192351,
Japanese Patent Publication No. 3-56455 discloses a method for producing perhalomethanesulfonate by synthesizing perhalomethanesulfinate from perhalomethane bromide and dithionite, and oxidizing this. ing. When a highly reactive perhalomethane iodide is applied in these production methods, it is difficult to separate the product, perhalomethanesulfinate, and by-produced sodium iodide. Furthermore, Japanese Patent Publication No. 3-56455 describes that perhalomethanesulfonate is oxidized to produce perhalomethanesulfonate, but it is extremely problematic that iodide ions remain. It has been reported that

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a sulfonate in the prior art, in which it is difficult to separate iodate and iodate which are by-produced from the target substance. It is to easily remove the iodide salt which is a by-product.

[0006]

Means for Solving the Problems The present inventors have made intensive studies in view of such a situation, and as a result, have found that the general formula (1) (R ¹ SO ₃ ) nM ¹ . ··· (1) (where R ¹ is an alkyl group, an allyl group, an aryl group, a perfluoroalkyl group, M ¹ is hydrogen, an organic group, a 1 to 3 valent metal, and n is an integer of 1 to 3) (2) (R ² SO ₂ ) mM ² (2) (where R ² is an alkyl group, an allyl group, an aryl group,
A perfluoroalkyl group, M ² is hydrogen, an organic group, 1 to
A sulfinic acid compound represented by a trivalent metal, m is an integer of 1 to 3) and a general formula (3): M ³ X _l (3) ³ oxidizes a mixture containing an iodine compound represented by hydrogen, an ammonium group, a metal having 1 to 3 valences, X is iodine, and 1 is an integer of 1 to 3), and then removes iodine. It is intended to provide a method for purifying a sulfonic acid compound.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The sulfonic acid compound referred to in the present invention is represented by the general formula (1) (R ¹ SO ₃ ) nM ¹ (where R ¹ is an alkyl group, allyl group, aryl group, perfluoroalkyl group, M ¹ Is a sulfonic acid represented by hydrogen, an organic group, a metal having 1 to 3 valences, X is iodine, and n is an integer of 1 to 3) or a salt thereof. The sulfonic acid compounds in the present invention may be used alone or in a combination of two or more.

The sulfinic acid compound referred to in the present invention is represented by the general formula (2) (R ² SO ₂ ) nM ² (where R ² is an alkyl group, an allyl group, an aryl group, a perfluoroalkyl group, wherein M ² is A sulfinic acid represented by hydrogen, an organic group, a metal having 1 to 3 valences, and n is an integer of 1 to 3) or a salt thereof. The sulfinic acid compounds in the present invention may be used alone or in combination of two or more. Such a sulfinic acid compound is substantially converted into a sulfonic acid compound by being oxidized in the purification method of the present invention.

The iodine compound referred to in the present invention is a compound represented by the following general formula (3): M ³ X ₁ (where M ³ is hydrogen, an ammonium group,
-Trivalent metal, X is iodine, l is an integer of 1-3), and there are no particular restrictions. Specific compounds include lithium iodide, potassium iodide, sodium iodide, and iodine. Examples thereof include calcium iodide, magnesium iodide, aluminum iodide, and ammonium iodide. It is needless to say that the present invention is not limited to only these specific examples.

The conditions for performing the oxidation in the present reaction are not particularly limited. However, from the viewpoint of controlling the heat generated during the progress of the reaction, the oxidation is preferably performed in the presence of a solvent.
Specific examples of the solvent used here include water, pentane,
Hydrocarbon solvents such as hexane, heptane, octane, nonane, decane, undecane and dodecane; fluorine solvents such as perfluorohexane, perfluorooctane and inert liquid; dichloromethane, chloroform, carbon tetrachloride, 1,1,2,2 2-tetrachloroethane, 1,1,
Chlorinated solvents such as 1,2-tetrachloroethane, alcohols such as methanol, ethanol, isopropyl alcohol, n-butanol, iso-butanol, tert-butanol, acetone, methyl ethyl ketone , Methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, methyl cellosolve, cellosolve,
Aprotic polar solvents such as butyl cellosolve, butyl carbitol, tetrahydrofuran, and dioxane; and aromatic solvents such as benzene, toluene, and xylene. Of course, these specific examples do not limit the present invention in any way.

In the present invention, one of these solvents may be used alone, or two or more thereof may be used in any combination. When two or more solvents are used, the system need not be uniform, and there is no particular problem even if the system is a liquid-liquid, two-layer system, or dispersion system.

The amount of the solvent is not particularly limited.
In particular, any amount can be used as long as the oxidation of the iodine compound in the system can proceed. In particular, the amount does not need to be such that the mixture to be purified and the oxidizing agent are completely dissolved.

The oxidation reaction temperature in the present invention is not particularly limited, but when the reaction temperature is extremely low, a long reaction time is required, and the reaction temperature is higher than the boiling point of the solvent used. In such a case, it is necessary to use equipment such as an autoclave. Therefore, the reaction temperature is preferably 0
C to the boiling point of the solvent used.

In the present invention, as a method for oxidizing the sulfinic acid compound represented by the general formula (2) and the iodine compound represented by the general formula (3) existing in the system, a known and commonly used oxidation method can be used. Particularly, a method using an oxidizing agent is useful from an industrial viewpoint. The oxidizing agent used here is not particularly limited, but specific examples thereof include aqueous hydrogen peroxide, hypochlorite, permanganate, and concentrated sulfuric acid. As particularly preferred oxidizing agents, from the viewpoint of ease of post-treatment,
Hydrogen peroxide solution. An oxidation method by blowing air or oxygen gas into the system is also applicable.

The amount of the oxidizing agent used is not particularly limited, but is preferably at least 1 equivalent to 1 equivalent of the iodine compound, and when a sulfinic acid compound is present,
One equivalent or more is preferable per one equivalent of the total of the iodine compound and the sulfinic acid compound.

When an aqueous hydrogen peroxide solution is used as the oxidizing agent, the pH of the reaction system is preferably 6 or less, more preferably p
By performing oxidation in an acidic region of H1 or less, the reaction can be made to proceed more quickly. This is because, as described below, the protons capture the hydroxide ions that are by-produced when oxidizing the iodine anion in the reaction system and converting it to iodine molecules, and the equilibrium of the reaction is biased in the direction that generates iodine molecules. it is conceivable that. It is needless to say that the present invention is not limited at all by this consideration. 2X ⁻ + 2H ₂ O ₂ → X ₂ + OH ⁻ (X:
Iodine)

In the present invention, the sulfonic acid compound is purified by removing iodine generated by the oxidation reaction. As a method for removing iodine, a known and used removal method can be used. For example, heating and / or reducing the iodine (I
_{There is} a method of distilling off ₂ ) and a method of extracting with an organic solvent in which iodine is soluble but sulfonic acid compound has poor solubility. From the standpoint of industrial convenience and economy, a method of extracting with an organic solvent in which iodine is soluble is preferred.

Examples of the organic solvent which can be used for the extraction include hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane and dodecane; and fluorine solvents such as perfluorohexane, perfluorooctane and inert liquid. , Dichloromethane, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane, 1,1,1,2-tetrachloroethane and other chlorinated solvents, methanol, ethanol, isopropyl alcohol
, N-butanol, iso-butanol, tert-
Alcohols such as butanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, butyl acetate, dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, methyl cellosolve, cellosolve, butyl cellosolve, butyl carbitol, tetrahydrofuran And aprotic polar solvents such as dioxane, and aromatic solvents such as benzene, toluene, and xylene. Of course, these specific examples do not limit the present invention in any way.

In the present invention, only one of these solvents may be used alone, or two or more thereof may be used in any combination.

As the extraction solvent, those having poor solubility of the sulfonic acid compound obtained as a purified product are preferable, and hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane, decane, undecane and dodecane, benzene, One or more of aromatic solvents such as toluene and xylene are preferable.

When the sulfonic acid compound obtained as a purified product has a high solubility in water, industrially significant methods include dissolving the compound in water to form an aqueous solution, and then using an organic solvent to prepare iodine. Is preferable.

Further, the number of times of purification according to the present invention is not limited, and the purity of the sulfonic acid compound obtained by repeating this method can be further increased.

Since the sulfonic acid compound obtained by the purification method according to the present invention has sufficiently removed the iodine compound as an impurity, it has various surfactants, flame retardants, especially flame retardants for polycarbonate, and various kinds of organic chemical reactions. It can be used as a catalyst or the like.

[0024]

The present invention will be described in more detail with reference to the following Examples, which, of course, are not intended to limit the present invention.

(Example 1) 18.4 g of 1-iodobutane
Then, 50 g of water was added to 25.2 g of sodium hydrogen sulfite and an autoclave reactor, and reacted at 180 ° C. for 24 hours. After the completion of the reaction, the content was transferred to a 1 L flask, and 200 g of 10% sulfuric acid was gradually added to adjust the pH of the mixed solution to 1. Then, 100m of hydrogen peroxide water (35%) gradually
L, and the mixture was stirred at room temperature for 1 hour. Hexane 200m
In L, the aqueous layer was washed twice. Thereafter, the pH was adjusted to 7 with sodium hydroxide, and the aqueous layer was concentrated. The sulfonate was extracted with hot acetone as an extraction solvent, and then the solvent was removed to obtain a highly pure sulfonate. Purity was measured by elemental analysis (C, H, S). Elemental analysis result Theoretical value (C, H, S) = (30.00,-, 20.0)
2) Actual value (C, H, S) = (29.98, −, 19.
9)

10 g of sodium perfluorobutylsulfonate and 8 g of sodium iodide were added to 200 mL of water.
A mixed aqueous solution of a sulfonate and an iodide salt was prepared. 10 g of concentrated sulfuric acid was added to this (pH = 1). To this solution was added 50 mL of aqueous hydrogen peroxide (35%), and the mixture was stirred at room temperature for 1 hour. The aqueous layer was washed twice with 100 mL of hexane. Then, with sodium hydroxide, pH
Was adjusted to 7, and the aqueous layer was concentrated. The sulfonate was extracted with hot acetone as an extraction solvent, and then the solvent was removed to obtain a highly pure sulfonate. Purity was measured by elemental analysis (C, H, S). Elemental analysis result Theoretical value (C, H, S) = (14.92, −, 9.9)
5) Actual value (C, H, S) = (14.92, −, 9.9)

Examples 3 to 6 The same procedure as in Example 2 was carried out except that the sulfonate and the sulfinate were the following compounds. The results are shown in Table 1 below.

[0028]

[Table 1]

[0029]

According to the purification method of the present invention, a sulfonic acid compound and a sulfinic acid compound can be easily purified with high purity without using any special equipment.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H006 AA02 AD16 AD30 BB11 BC53 BE32

Claims (7)

[Claims] (1) (1) (R ¹ SO ₃ ) nM ¹ (1) (where R ¹ is an alkyl group, an allyl group, an aryl group, a perfluoroalkyl A group, M ¹ is hydrogen, an organic group, a metal having 1 to 3 valences, n is an integer of 1 to 3) and / or a sulfonic acid compound represented by the general formula (2) (R ² SO ₂ ) mM ^2. ... (2) (where R ² is an alkyl group, an allyl group, an aryl group,
A perfluoroalkyl group, M ² is hydrogen, an organic group, 1 to
A sulfinic acid compound represented by a trivalent metal, m is an integer of 1 to 3) and a general formula (3): M ³ X _l (3) (where M ³ oxidizes a mixture containing an iodine compound represented by hydrogen, an ammonium group, a metal having 1 to 3 valences, X is iodine, and l is an integer of 1 to 3), and then removes iodine. A method for purifying a sulfonic acid compound. 2. A general formula (1) R ¹ and the general formula in (2), the purification method of claim 1, wherein R ² in the general formula (2) is characterized in that it is a perfluoroalkyl group 3. The purification method according to claim 1, wherein the method is oxidized with an oxidizing agent. 4. The method according to claim 3, wherein the oxidizing agent is hydrogen peroxide. 5. The method according to claim 3, wherein the pH of the system when the oxidizing agent is used is 6 or less. 6. The purification method according to claim 1, wherein iodine is removed using an organic solvent that dissolves iodine. 7. The purification method according to claim 6, wherein the organic solvent is an aromatic solvent and / or a hydrocarbon solvent.