JP2003252848A - Method for producing sulfonic acid anhydride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily and economically producing sulfonic acid anhydride from sulfonic acid. <P>SOLUTION: The method for synthesizing the sulfonic acid anhydride from the sulfonic acid comprises reacting the sulfonic acid with anhydrides of mixed acids comprising the sulfonic acid and a carboxylic acid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a sulfonic acid anhydride. More specifically, the present invention relates to a method for efficiently producing a sulfonic acid anhydride by reacting a sulfonic acid and a mixed acid anhydride containing a sulfonic acid and a carboxylic acid.

[0002]

2. Description of the Related Art A commonly used method for producing a sulfonic acid anhydride is to dehydrate a corresponding sulfonic acid with dicyclohexylcarbodiimide (hereinafter abbreviated as DCC), thionyl chloride, diphosphorus pentoxide or the like. Well known. However, these known methods require expensive D
It is necessary to use CC, thionyl chloride, diphosphorus pentoxide, etc. in a considerable amount with respect to the sulfonic acid as a substrate, and further, there is a problem of yield, and it is difficult to operate at the time of reaction and regeneration of dehydrating agent. Due to some problems, it is not always an economical and easy method, and efficient synthetic methods to replace them have been expected.

Regarding an efficient method for synthesizing sulfonic anhydride,
In addition to the above, studies using various reagents have been conducted. For example, a method of mixing and heating paratoluenesulfonic acid with diphenylmercury and tributylphosphine in benzene to obtain paratoluenesulfonic anhydride together with mercury and tributylphosphine oxide (T. Muk
aiyama, I .; Kuwajima, Z. S
uzuki, J .; Org. Chem. , 28,
2024 (1963)) or methoxyacetylene and p-toluenesulfonic acid are reacted in methylene chloride to obtain p-toluenesulfonic acid anhydride together with methyl acetate (G, Eglinton, ER.
H. Jones, B.A. L. Shaw, M .;
C. Whiting, J.M. Chem. So
c. , 1860 (1954)), or a method of reacting paratoluenesulfonic acid with succinic dichloride to obtain paratoluene anhydride together with succinic anhydride and hydrogen chloride (MH Karger, Y. Mazu).
r, J. Org. Chem. , 36, 528
(1971)) and the like have been proposed.

However, none of these paratoluenesulfonic acid anhydride synthesis methods is necessarily satisfactory as an industrial production method because of the high cost of reagents and insufficient yield. Regarding benzenesulfonic anhydride, silver benzenesulfonate is heated to reflux in acetyl chloride, filtered, and then heated at 100 ° C.-0.1 m.
Method of synthesis by distillation at mHg (WF
lovell, N.N. C. Ross, J.M. Che
m. Soc. , 5474 (1964)) further mixes methanesulfonic acid and acetyl chloride for heating and reflux under heating, and removes excess acetyl chloride by distillation to obtain methanesulfonic anhydride ( MH Karge
r, Y. Mazur, J .; Org. Che
m. , 36, 528 (1971)) have been proposed, but none of them have been able to overcome economic problems.

Acetyl paratoluene sulfonate, which is a mixed acid anhydride that can be synthesized from paratoluene sulfonic acid and acetic anhydride, decomposes relatively easily (30 ° C., 12 h) in the presence of a trace amount of dimethyl ether, and is almost completely decomposed. It was reported that it was disproportionated to para-toluene sulfonic anhydride and acetic anhydride, and it was also possible to synthesize acetyl methane sulfonate from acetyl chloride and methane sulfonic acid, which can also be synthesized from methane sulfonic acid and acetic anhydride. To reduce the content of residual methanesulfonic acid to 5%, and distill under reduced pressure at 120 ° C.-10 ⁻³ mmHg to yield methanesulfonic anhydride in a yield of 50%.
Reported that they succeeded in gaining strength (both MH.
Karger, Y .; Mazur, J .; Or
g. Chem. , 36, 528 (1971))
However, all of them have problems such as very long reaction time and distillation process at high temperature and high vacuum. Further, regarding the latter reaction in the literature, the disproportionation of acetyl methane sulfonate to methane sulfonic anhydride and acetic anhydride is considered only as a reaction catalyzed by an acid called methane sulfonic acid, and mixed acid anhydride and sulfonic acid are considered. Nothing is said about the 1: 1 correspondence reaction with.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems and to provide a method for easily and economically producing sulfonic acid anhydrides.

[0007]

Means for Solving the Problems As a result of intensive studies on the synthesis method of sulfonic acid anhydride, the present inventors have found that sulfonic acid, sulfonic acid and carboxylic acid can be prepared without using an expensive dehydrating agent or reaction reagent. The present inventors have found that a sulfonic acid anhydride can be obtained more easily and economically than in the past by mixing and reacting with a mixed acid anhydride consisting of That is, the gist of the present invention is a method of synthesizing a sulfonic acid anhydride from a sulfonic acid, which comprises reacting a sulfonic acid and a mixed acid anhydride composed of a sulfonic acid and a carboxylic acid. It depends on the manufacturing method.

In a preferred embodiment of the present invention, in the method for producing a sulfonic acid anhydride, the sulfonic acid is selected from an aromatic sulfonic acid or an aliphatic sulfonic acid, for example, benzenesulfonic acid which may have a substituent or Alkyl sulphonic acid, especially paratoluene sulphonic acid, iodobenzene sulphonic acid, benzene sulphonic acid, methane sulphonic acid or trifluoromethane sulphonic acid, the carboxylic acid being an aliphatic or aromatic carboxylic acid, especially acetic acid or propion It can be mentioned that it is a relatively inexpensive carboxylic acid represented by an acid or the like, and more preferably acetic acid. In addition, as another preferred embodiment of the present invention, in the method for producing a sulfonic acid anhydride, a mixed acid anhydride composed of a sulfonic acid and a carboxylic acid is used in a range of 0.1 to 10 equivalents based on the sulfonic acid. And that the reaction temperature is between −10 ° C. and 250 ° C. In addition, the substrate concentration should be as high as possible,
In order to increase the reaction rate, it is a preferable mode to carry out the reaction substantially without solvent. Although the reaction on the solid surface is also possible, it is preferable to carry out the reaction in the form of a solution or a slurry, so that the melting point of the reaction raw material mixture of sulfonic acid and a mixed acid anhydride consisting of sulfonic acid and carboxylic acid is A preferable mode is 250 ° C. or lower.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below. (Sulfonic Acid) The sulfonic acid as a raw material used in the synthesis reaction of the present invention is not limited to any known sulfonic acid. Specific examples of the sulfonic acid include benzenesulfonic acid, paratoluenesulfonic acid, m-xylene-
Alkylbenzenesulfonic acids such as 4-sulfonic acid, paraoctylbenzenesulfonic acid, paradodecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid and mesitylenesulfonic acid, biphenylsulfonic acid, and 1 -Alkylnaphthalenesulfonic acids such as naphthalenesulfonic acid, 2-naphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid, diisobutylnaphthalenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid,
Examples thereof include alkyl sulfonic acids such as hexane sulfonic acid and octane sulfonic acid, and polyvalent sulfonic acids such as mesitylene disulfonic acid and benzene-m-disulfonic acid. Also, these sulfonic acids have C on their carbon.
It may contain a halogen such as l, Br or F, or a substituent such as an acyl group or an alkoxy group. Among them, alkyl or aryl sulfonic acids having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, such as methane sulfonic acid, benzene sulfonic acid, paratoluene sulfonic acid, mesitylene sulfonic acid, trifluoromethane sulfonic acid are preferably applied, and particularly, Paratoluenesulfonic acid, iodobenzenesulfonic acid, benzenesulfonic acid, methanesulfonic acid and trifluoromethanesulfonic acid are preferred.

(Mixed Acid Anhydride Composed of Sulfonic Acid and Carboxylic Acid) In the present invention, the "mixed acid anhydride composed of sulfonic acid and carboxylic acid" means a compound obtained by dehydration condensation of sulfonic acid and carboxylic acid. To do. Specifically, sulfonic acid is R ¹ -SO ₃ H and carboxylic acid is R ² -COOH.
When represented by, the compound is represented by the following formula (I).

[0011]

[Chemical 1]

The amount of the mixed acid anhydride used in the present invention is
Although not particularly limited, it is generally used in the range of about 0.1 to 10 equivalents, preferably 0.2 to 5 equivalents, more preferably 0.25 to 4 equivalents, relative to the sulfonic acid. If it is too small beyond this range, the yield of sulfonic acid anhydride per sulfonic acid cannot be sufficiently obtained, while if it is too large, on the contrary, the yield of sulfonic acid anhydride per mixed acid anhydride cannot be sufficiently obtained. In some cases, the separation from the desired sulfonic acid anhydride may not be easy. Further, rather than the intended main reaction, the disproportionation reaction that decomposes the mixed acid anhydride into a sulfonic acid anhydride and a carboxylic acid anhydride by using sulfonic acid as a catalyst is overwhelmingly prioritized. Will end up.

(Sulfonic Acid in Mixed Acid Anhydride) The sulfonic acid forming the mixed acid anhydride used in the present invention may be the same as or different from the sulfonic acid used in the above reaction substrate. Well, the sulfonic acids mentioned above are preferably used. When they are the same, the target sulfonic anhydride is a symmetrical compound, and when they are different, it is an asymmetric compound.

(Carboxylic Acid in Mixed Acid Anhydride) The carboxylic acid forming the mixed acid anhydride used in the present invention is a linear carboxylic acid such as acetic acid, propionic acid, butyric acid, isobutyric acid or cyclohexyl acetic acid. In addition to the aliphatic carboxylic acids, maleic acid, succinic acid, cyclohexanedicarboxylic acid and other aliphatic dicarboxylic acids, and various carboxylic acids such as phthalic acid and benzoic acid can also be used. Further, in all of these carboxylic acids, the hydrogen atom on carbon in the molecule may be replaced with a halogen atom, an acyl group, an alkoxy group or the like. When these carboxylic acids are applied to the present invention as a mixed acid anhydride with sulfonic acid, a carboxylic acid derived from the mixed acid anhydride is produced at the same time as the desired sulfonic acid anhydride, so that the desired sulfone is produced from the reaction system. It is important to appropriately select in consideration of the combination with sulfonic acid so that the acid anhydride can be finally separated. Of these, a carboxylic acid having a boiling point of 300 ° C. or lower is preferable, and acetic acid is particularly preferable.

(Solvent or Additive) In the sulfonic acid anhydride synthesis reaction of the present invention, particularly from the economical point of view, in addition to the sulfonic acid and the mixed acid anhydride, the reaction solvent and the additive are particularly preferable. Without using
It can be carried out substantially without solvent. Alternatively, an additive or a solvent may be used in the synthesis reaction of sulfonic anhydride. In that case, what is preferably used is
For example, n-hexane, n-heptane, n-octane,
aliphatic hydrocarbon compounds such as n-dodecane, benzene, toluene, xylene, mesitylene, monochlorobenzene,
Aromatic hydrocarbon compounds such as methoxybenzene, nitrile compounds such as acetonitrile, propanenitrile, capronitrile, adiponitrile, benzonitrile, tolunitrile, dimethyl phthalate, dibutyl phthalate, dimethyl malonate, dimethyl succinate, ethyl acetate, methyl acetate, etc. Ester compounds, dimethyl ether, diethyl ether, diglyme, tetrahydrofuran and other ether compounds, methylene chloride, chloroform, dichloroethane and other halogenated alkyl compounds, dimethylformamide,
Examples thereof include amide compounds such as 1,3-dimethyl-2-imidazolidinone. Of these, ethers such as tetrahydrofuran, nitriles such as acetonitrile, alkyl halides and the like are preferable in terms of reaction. Also,
These can be used alone or as a mixture. Further, a small amount of carboxylic acid such as acetic acid or carboxylic acid anhydride can be added.

(Reaction conditions) In the production method of the present invention,
The reaction of forming sulfonic acid anhydride from sulfonic acid is as shown in the following formula (II). In this example, paratoluenesulfonic acid is used as the raw material sulfonic acid, and acetylparatoluenesulfonate is used as the mixed acid anhydride of carboxylic acid and sulfonic acid, and the target sulfonic acid anhydride is paratoluenesulfonic acid anhydride. .

[0017]

[Chemical 2]

Acetyl paratoluene sulfonate (A)
And para-toluenesulfonic acid (B) react with each other to produce para-toluenesulfonic acid anhydride (C) and acetic acid (D).

Acetyl paratoluene sulfonate (A)
This reaction in which paratoluenesulfonic acid (B) reacts with paratoluenesulfonic acid anhydride (C) and acetic acid (D) is considered to be an equilibrium reaction. Usually, the reaction proceeds sufficiently without removing the product species from the system in the course of the reaction, but because of the equilibrium reaction, either one or both of the sulfonic acid anhydride or the carboxylic acid that is produced can be removed from the reaction system. The positive reaction may be allowed to proceed further.

In the production method of the present invention, the method of removing the product sulfonic anhydride and / or carboxylic acid from the reaction system is not particularly limited, but specifically, 1) a method of distilling under reduced pressure. 2) a method of circulating an inert gas with respect to the reaction and distilling off with entrainment, 3) a method of crystallization and the like. These removal methods may be used alone or in combination.

The pressure for distilling off the produced sulfonic anhydride and / or carboxylic acid under reduced pressure may be lower than atmospheric pressure, but the boiling point of the desired sulfonic anhydride and the sulfonic acid as a reaction product The degree of pressure reduction and the pressure reduction time are selected in consideration of the boiling points of the mixed acid anhydride and the carboxylic acid as a by-product. Of the sulfonic acids, mixed acid anhydrides, sulfonic anhydrides, and carboxylic acids present in the reaction system, the boiling point of the carboxylic acid is often the lowest, so in a preferred embodiment, only the carboxylic acid is added from the reaction system. It is distilled off under reduced pressure. In this case, the boiling point of the carboxylic acid at atmospheric pressure is preferably 300 ° C. or lower, more preferably 200 ° C. or lower, particularly preferably 150 ° C. or lower. Further, the boiling point of the carboxylic acid under reduced pressure is preferably 30 ° C. or more lower than the other components, and more preferably 50 ° C. or more lower.

Examples of the inert gas used for distilling off the sulfonic acid anhydride and / or carboxylic acid which are the products by circulating an inert gas to the reaction include, for example, argon, helium, Examples thereof include neon, nitrogen, methane, ethane, propane, or a mixed gas thereof. When distilling off with gas, the gas flow rate should be determined in consideration of the volatility of the target sulfonic acid anhydride, the volatility of the reaction product sulfonic acid and mixed acid anhydride, and the volatility of the by-product carboxylic acid. And select the distribution time. As in the case of distilling off under reduced pressure as described above, the volatility of the carboxylic acid is often the highest among the reaction substrates and products, so in a preferred embodiment, only the carboxylic acid is distilled off from the reaction system into the gas. To do.

In the case of crystallizing the sulfonic acid anhydride and / or carboxylic acid which are the products, there are methods such as lowering the temperature for the crystallization in the middle of the reaction or adding a poor solvent.
When it is removed from the system by low temperature crystallization, the melting point of the mixture of the reactant species and the product species that should remain as a liquid needs to be lower than the melting point of the desired sulfonic acid anhydride or carboxylic acid that is a by-product. It is necessary to determine the reaction temperature and the composition ratio in consideration of the melting point of. Further, it is necessary to consider the melting point in advance when selecting the carboxylic acid used as the mixed acid anhydride of the substrate. When using a poor solvent, sulfonic acid anhydride and sulfonic acid to the poor solvent to be used, mixed acid anhydride, also considering the solubility of the carboxylic acid, the type of carboxylic acid, the poor solvent species, and further the mixing ratio of the raw materials, It is necessary to determine the amount of poor solvent.

Of the sulfonic acids, mixed acid anhydrides, sulfonic acid anhydrides, and carboxylic acids present in the reaction system, the sulfonic acid anhydride has the highest melting point and often has a high crystallinity, so that it is a preferred embodiment. Is to remove only the sulfonic acid anhydride from the reaction system by crystallization. In this case, the melting point of the sulfonic acid anhydride is preferably 80 ° C. or higher,
C. or higher is more preferable, and 120.degree. C. or higher is particularly preferable.
In addition, the boiling point of sulfonic anhydride is 30 than that of other components.
It is preferably higher than 0 ° C, more preferably higher than 50 ° C.

In the present invention, the phrase "the reaction is carried out while removing the produced sulfonic acid anhydride and / or carboxylic acid from the reaction system" means that the sulfonic acid anhydride or carboxylic acid is removed at any point during the reaction. It means that one or both of the above are added, and not only the operation of continuously removing during the reaction but also the operation of intermittently removing may be performed. Further, when both are removed, both may be removed at the same time, or either one may be removed first.

In another preferred embodiment of the production method of the present invention, the reaction is carried out substantially without solvent.
Substantially solvent-free, in the reaction system, in the range that does not have any adverse effect on the reaction, and does not substantially reduce the concentration of the substrate,
It does not prevent the presence of an inert gas or solid, and specifically means that the solvent substance other than the substrate and the reaction product in the reaction mixture is 5% by weight or less, preferably 2% by weight or less. To do. By not using a solvent, the substrate concentration can be increased, the reaction rate can be increased, and the treatment after the reaction can be simplified. Further, in the case of this reaction, high selectivity can be achieved without using a solvent.

Even if either or both of the substrate sulfonic acid and the mixed acid anhydride consisting of sulfonic acid and carboxylic acid are solid, if the reaction raw material mixture is melted at the reaction temperature, it is substantially The reaction can be carried out without solvent. Therefore, the melting point of the reaction raw material mixture of sulfonic acid and a mixed acid anhydride composed of sulfonic acid and carboxylic acid is preferably 250 ° C. or lower, more preferably 200 ° C. or lower. It is particularly preferably 130 ° C. or lower.

The conditions for carrying out the method of the present invention are not particularly limited, but the reaction temperature is usually from -10 ° C to 250 ° C,
It is preferably carried out in the range of 0 ° C to 200 ° C, more preferably 0 ° C to 130 ° C. The reaction pressure is also not particularly limited, and the reaction is carried out under reduced pressure to increased pressure. Also,
It is also possible to carry out the reaction while circulating an inert gas or the like. Furthermore, according to the method of the present invention, the mixed acid anhydride can be reacted at a lower temperature than the disproportionation reaction in which the mixed acid anhydride is decomposed into the sulfonic acid anhydride and the carboxylic acid anhydride. It has been found that the color is light and there are few impurities.

In the present invention, the reaction proceeds regardless of whether the sulfonic acid or the mixed acid anhydride is charged into the reactor first. Also,
The reaction proceeds even if one of them is first heated to a predetermined temperature and then the other is added. Furthermore, regarding the combination of heating, pressure operation, and gas flow, a combination method can be appropriately selected according to the reaction substrate.

The reaction system for carrying out the reaction of the present invention is not particularly limited, and either batch reaction or continuous flow reaction can be carried out. The type of reactor is also not particularly limited, and a general reactor such as a reactor having one tank or two or more continuous stirring tanks, a tubular reactor, and the like can be used. Since an acid is used in the present invention, it is preferable to use a corrosion resistant material for the reactor material, such as stainless steel, Hastelloy, Monel,
Examples include Inconel, titanium, titanium alloys, zirconium, zirconium alloys, nickel, nickel alloys, tantalum, fluororesins, and materials coated with various kinds of glass on the inside. It is preferable that the sulfonic acid, the mixed acid anhydride, the reaction solvent, the flowing gas, etc. used in the reaction are subjected to the reaction after the water is sufficiently removed in advance.

The reaction format of the present invention will be described below with reference to an example of a palindromic reaction. Sulfonic acid and mixed acid anhydride are supplied to a reactor together with a solvent if necessary, and reacted at a predetermined temperature and a predetermined pressure for a desired time and mixed with the produced sulfonic acid anhydride, carboxylic acid and unreacted sulfonic acid. The reaction mixture containing the acid anhydride is removed. By appropriately selecting the reaction conditions, the sulfonic acid anhydride can be recovered with extremely high selectivity, and further purification is not required. However, it is also possible to carry out purification by distillation, crystallization, washing, extraction, etc., if necessary.

[0032]

EXAMPLES The present invention will be specifically described with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In the following examples, the yield (%) of the sulfonic acid anhydride was expressed as a percentage of the molar ratio of the produced sulfonic acid anhydride to the charged mixed acid anhydride.
Further, in Example 7, the disproportionation reaction of acetyl paratoluene sulfonate also occurs at 60 ° C. due to the catalytic action of paratoluene sulfonic acid.

[Example 1] A 50 ml eggplant-shaped flask dried by a drier was replaced with dry nitrogen, and then 24.3 g (140.9 mmol) of paratoluenesulfonic acid and 10.0 g (46.7 mmo) of acetylparatoluenesulfonate.
1) was charged and heated to 70 ° C. in a nitrogen atmosphere in an oil bath and stirred for 1 hour. At this temperature, with this composition, a part of the paratoluenesulfonic acid anhydride formed in the reaction was crystallized in the reaction solution. Then, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen to
It was analyzed by 1 H-NMR. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 69% based on the charged acetylparatoluenesulfonate. The main impurities contained were residual paratoluenesulfonic acid, acetylparatoluenesulfonate and acetic acid.

Next, 9.5 g (93.4 g) of acetic anhydride was added to the crude paratoluenesulfonic acid anhydride under a dry nitrogen atmosphere.
mmol) and stirred at 25 ° C. for 10 minutes to form a slurry, and then filtered under reduced pressure in a dry air atmosphere, and 19.3 g (188.9 mmol) of acetic anhydride is sprinkled over the filter residue to rinse it. I went. The obtained cake was dried at 25 ° C. under reduced pressure at about 500 Pa for 2 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic anhydride was 48% in terms of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic anhydride was 99.7%. . At this time, 0.3% of acetyl paratoluene sulfonate was contained as an impurity.

Example 2 A 50 ml eggplant-shaped flask dried with a drier was replaced with dry nitrogen, and then 8.0 g (46.4 mmol) of paratoluenesulfonic acid and 9.7 g (45.1 mmol) of acetylparatoluenesulfonate were added. And heat to 70 ° C in an oil bath under a nitrogen atmosphere,
Stir for 30 minutes. At this temperature, with this composition, a part of the paratoluenesulfonic acid anhydride formed in the reaction was crystallized in the reaction solution. Then, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and 1H-NM was added.
Analyzed by R. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 32% based on the charged acetylparatoluenesulfonate.

Next, 3.8 g (37.2 g) of acetic anhydride was added to the crude p-toluenesulfonic acid anhydride under a dry nitrogen atmosphere.
mmol) and stirred at 25 ° C. for 20 minutes to form a slurry, and then vacuum filtration is performed in a dry air atmosphere, and 4.7 g (46.4 mmol) of acetic anhydride is sprinkled on the filter residue to rinse it. I went. The cake obtained is 2
It was dried under reduced pressure at about 500 Pa at 5 ° C. for 2.5 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic anhydride was 28% in terms of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic anhydride was 99.6%. . At this time, as impurities, 0.3% of acetyl paratoluene sulfonate and 0.1% of acetic acid were contained.

Example 3 After replacing 20 ml of Schlenk dried by a dryer with dry nitrogen, 0.3 g (1.8 mmol) of paratoluenesulfonic acid and 0.8 g (3.6 mmol) of acetylparatoluenesulfonate were charged. In a nitrogen atmosphere, the mixture was heated to 60 ° C in an oil bath and stirred for 30 minutes. At this temperature, with this composition, a part of the paratoluenesulfonic acid anhydride formed in the reaction was crystallized in the reaction solution. Thereafter, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and analyzed by 1H-NMR. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 23% based on the charged acetylparatoluenesulfonate.

Next, 0.4 g (3.6 m) of acetic anhydride was added to the crude paratoluenesulfonic acid anhydride under a dry nitrogen atmosphere.
mol) and stirred at 25 ° C. for 10 minutes to form a slurry, and then filtered under reduced pressure in a dry air atmosphere, and 1.6 g (16.0 mmol) of acetic anhydride is sprinkled on the filter residue to rinse it. I went. The cake obtained is 25
It was dried under reduced pressure at about 100 Pa for 2.5 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic acid anhydride was 13% in terms of the amount of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic acid anhydride was 99.6%. . At this time, as impurities, 0.3% of acetyl paratoluene sulfonate and 0.1% of acetic acid were contained.

[Example 4] A 50 ml eggplant-shaped flask dried by a drier was replaced with dry nitrogen, and then 0.5 g (3.1 mmol) of paratoluenesulfonic acid and 2.0 g (9.1 mmol) of acetylparatoluenesulfonate. And warm it to 60 ° C in an oil bath under a nitrogen atmosphere,
Stir for minutes. At this temperature, with this composition, a part of the paratoluenesulfonic acid anhydride formed in the reaction was crystallized in the reaction solution. Thereafter, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and analyzed by 1H-NMR. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 17% based on the charged acetylparatoluenesulfonate.

Next, 0.9 g (9.1 m) of acetic anhydride was added to the crude paratoluenesulfonic acid anhydride under a dry nitrogen atmosphere.
mol) and stirred at 25 ° C. for 20 minutes to form a slurry, and then filtered under reduced pressure in a dry air atmosphere, and 2.5 g (24.5 mmol) of acetic anhydride is sprinkled on the filter residue to rinse it. I went. The cake obtained is 25
It was dried under reduced pressure at about 200 Pa for 2 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic anhydride was 12% in terms of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic anhydride was 99.8%. . At this time, as impurities, acetyl paratoluene sulfonate was contained in an amount of 0.2% and acetic acid was contained in a very small amount.

Example 5 A 50 ml eggplant-shaped flask dried with a drier was replaced with dry nitrogen, and then 5.4 g (31.1 mmol) of paratoluenesulfonic acid and 2.3 g (10.8 mmol) of acetylparatoluenesulfonate were added. And heat to 60 ° C in an oil bath under a nitrogen atmosphere,
Immediately thereafter, the pressure was reduced to about 500 Pa and the mixture was stirred for 30 minutes. At this temperature, with this composition, a significant part of the paratoluenesulfonic acid anhydride formed in the reaction crystallized in the reaction solution. Thereafter, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and analyzed by 1H-NMR. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 91% based on the charged acetylparatoluenesulfonate.

Next, 1.4 g (14.0 g) of acetic anhydride was added to the crude paratoluenesulfonic acid anhydride under a dry nitrogen atmosphere.
mmol) and stirred at 25 ° C. for 20 minutes to form a slurry, and then filtered under reduced pressure in a dry air atmosphere, and 11.5 g (112.7 mmol) of acetic anhydride is sprinkled on the filter residue to rinse it. I went. The obtained cake was dried under reduced pressure at about 500 Pa at 25 ° C. for 3 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic acid anhydride was 77% in terms of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic acid anhydride was 99.9%. . At this time, as impurities, acetyl paratoluene sulfonate was contained in an amount of 0.1%, and acetic acid and acetic anhydride were contained in very small amounts.

Example 6 A 50 ml eggplant-shaped flask dried with a drier was replaced with dry nitrogen, and then 5.1 g (29.4 mmol) of paratoluenesulfonic acid and 5.7 g (26.6 mmol) of acetylparatoluenesulfonate were used. Was charged, the pressure was reduced to about 200 Pa, and immediately thereafter, the temperature was raised to 60 ° C. in an oil bath and the mixture was stirred for 30 minutes. At this temperature, with this composition, a significant part of the paratoluenesulfonic acid anhydride formed in the reaction crystallized in the reaction solution. Thereafter, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and analyzed by 1H-NMR. As a result, the yield of the obtained crude paratoluenesulfonic acid anhydride was 76% based on the charged acetylparatoluenesulfonate.

Next, 2.3 g (22.4 g) of acetic anhydride was added to the crude p-toluenesulfonic anhydride under a dry nitrogen atmosphere.
mmol) and stirred at 25 ° C. for 20 minutes to form a slurry, and then vacuum filtration is performed in a dry air atmosphere, and 13.3 g (130.7 mmol) of acetic anhydride is sprinkled on the filter residue to rinse it. I went. The obtained cake was dried under reduced pressure at about 500 Pa at 25 ° C. for 3 hours. The finally obtained purified paratoluenesulfonic acid anhydride (white) was dissolved in CDCl ₃ under nitrogen and analyzed by 1 H-NMR. As a result, the yield of paratoluenesulfonic anhydride was 63% in terms of acetylparatoluenesulfonate initially charged, and the weight percentage (purity) of paratoluenesulfonic anhydride was 99.9%. . As impurities at this time, 0.1% of acetyl paratoluene sulfonate and a very small amount of acetic acid were contained.

Example 7 A 50 ml eggplant-shaped flask dried with a drier was replaced with dry nitrogen, and then 0.4 g (2.3 mmol) of paratoluenesulfonic acid and 1.9 g (9.0 mmol) of acetylparatoluenesulfonate were used. Was charged to reduce the pressure to about 150 Pa, and immediately thereafter, the mixture was heated to 60 ° C. in an oil bath and stirred for 30 minutes. At this temperature, with this composition, a significant part of the paratoluenesulfonic acid anhydride formed in the reaction crystallized in the reaction solution. Thereafter, the reaction product obtained by cooling to 25 ° C. was dissolved in CDCl ₃ under nitrogen and analyzed by 1H-NMR. As a result, the yield of the obtained crude para-toluene sulfonic anhydride was 3 with respect to the charged acetyl para-toluene sulfonate.
It was 5%. The weight percentage (purity) of para-toluenesulfonic acid anhydride was 50.5%, and at this time, acetyl paratoluenesulfonate was 4% as an impurity.
0.1%, para-toluenesulfonic acid 8.4%, acetic acid 0.7%, and acetic anhydride 0.2% were contained.

[0046]

Industrial Applicability According to the method of the present invention, a sulfonic acid anhydride can be easily and economically produced from a sulfonic acid, which is an industrially advantageous method.

Claims (10)

[Claims] 1. A method for producing a sulfonic acid anhydride, which comprises reacting a sulfonic acid with a mixed acid anhydride composed of a sulfonic acid and a carboxylic acid in a method of synthesizing a sulfonic acid anhydride from a sulfonic acid. 2. The method for producing a sulfonic acid anhydride according to claim 1, wherein the reaction temperature is between −10 ° C. and 250 ° C. 3. The method for producing a sulfonic acid anhydride according to claim 1, wherein the mixed acid anhydride composed of sulfonic acid and carboxylic acid is used in an amount of 0.1 to 10 equivalents based on the sulfonic acid. 4. The reaction is carried out while distilling off the produced sulfonic anhydride and / or carboxylic acid under reduced pressure.
4. The method for producing a sulfonic acid anhydride according to any one of 3 above. 5. The reaction according to any one of claims 1 to 3, wherein a gas inert to the reaction is passed through the reaction system to carry out the sulfonic acid anhydride and / or the carboxylic acid produced while being distilled off. The method for producing a sulfonic acid anhydride according to 1. 6. The method for producing a sulfonic acid anhydride according to claim 1, wherein the reaction is carried out while removing the produced sulfonic acid anhydride and / or carboxylic acid from the system by crystallization. 7. The method for producing a sulfonic acid anhydride according to claim 1, wherein the sulfonic acid and a mixed acid anhydride composed of the sulfonic acid and the carboxylic acid are reacted substantially without solvent. 8. A melting point of a reaction raw material mixture of sulfonic acid and a mixed acid anhydride of sulfonic acid and carboxylic acid is 2
The method for producing a sulfonic acid anhydride according to claim 1, which has a temperature of 00 ° C. or lower. 9. The method for producing a sulfonic acid anhydride according to claim 1, wherein the carboxylic acid is acetic acid. 10. The method for producing a sulfonic acid anhydride according to claim 1, wherein the sulfonic acid is an alkyl or aryl sulfonic acid having 1 to 10 carbon atoms.