JP2003252850A - Method for producing salt of pentafluorobenzenesulfonic acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing salts of pentafluorobenzenesulfonic acid by sulfonating pentafluorobenzene without neutralizing the reaction liquid with a base such as barium carbonate, or without using the exchange of salts with the barium salt. <P>SOLUTION: The method for producing the salts of the pentafluorobenzenesulfonic acid by sulfonating the pentafluorobenzene with fuming sulfuric acid, and obtaining the salts of the pentafluorobenzenesulfonic acid from the aqueous solution of the pentafluorobenzenesulfonic acid comprises sulfonating the pentafluorobenzene, diluting the reaction mixture with water without neutralizing the reaction mixture, adding at least one kind selected from the group consisting of an alkali metal halide, and an alkali metal salt and quaternary ammonium salt of an organic material, or an aqueous solution thereof to the diluted mixture to precipitate and isolate the salts of the pentafluorobenzenesulfonic acid by crystallization. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing pentafluorobenzene sulfonates for isolating and producing pentafluorobenzene sulfonates which are useful as a photoacid generator for resists and a raw material for pharmaceuticals.

[0002]

2. Description of the Related Art As a metal salt of pentafluorobenzenesulfonic acid, pentafluorobenzene is sulfonated with fuming sulfuric acid, diluted with a large amount of water, the sulfuric acid is neutralized with barium carbonate, and barium sulfate is removed by filtration. A method of concentrating the filtrate and synthesizing it as barium pentafluorobenzenesulfonate is known (Journal of
Chemical Society (1959) 166-171). As a method for producing pentafluorobenzenesulfonic acid, there is known a method for obtaining pentafluorobenzenesulfonic acid monohydrate by treating barium pentafluorobenzenesulfonic acid synthesized by the above method with an ion exchange resin. (Journal of Fluorine Chemistry 12 (1978) 203-21
0).

[0003]

As described above, in the conventional method for producing an alkali salt of pentafluorobenzenesulfonic acid, etc., barium carbonate is obtained by neutralizing the reaction solution with barium carbonate after the sulfonation reaction as described above. It is taken out as salt. However, there is a problem that a large amount of barium sulfate is by-produced to neutralize the excess fuming sulfuric acid. In addition, barium carbonate is designated as a deleterious substance, which poses a danger to operators. Furthermore, in order to obtain sodium pentafluorobenzenesulfonate, it is necessary to synthesize pentafluorobenzenesulfonic acid and its barium salt, and further perform salt exchange and the like, which makes the operation more complicated and increases the number of steps. There is a problem that the yield decreases.

In view of the above-mentioned circumstances, the present invention, after the sulfonation reaction of pentafluorobenzene, does not neutralize the sulfuric acid in the reaction solution with a base such as barium carbonate, and also performs salt exchange from barium salt or the like. It is an object of the present invention to provide a method for producing pentafluorobenzene sulfonates, which produces pentafluorobenzene sulfonate without any treatment.

[0005]

Means for Solving the Problems As a result of intensive studies on the above technical problems, the present inventors have found that after the sulfonation reaction, an alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate is used. As a result of conducting a neutralization study, after the sulfonation reaction, the pentafluorobenzene sulfonates were precipitated by adding halides of alkali metals and their aqueous solutions without neutralizing the reaction mixture, and then filtering them by simple filtration. The inventors have found that they can be manufactured separately, and have completed the present invention.

According to the present invention, in a method for producing pentafluorobenzenesulfonates from an aqueous solution of pentafluorobenzenesulfonic acid obtained by sulfonating pentafluorobenzene with fuming sulfuric acid, the reaction mixture is treated with an intermediate solution after the sulfonation reaction. Dilute with water without hydration and add at least one selected from the group consisting of alkali metal halides, organic alkali metal salts and quaternary ammonium salts, or an aqueous solution thereof to add pentafluorobenzene sulfonate. A method for producing pentafluorobenzene sulfonates is characterized by crystallization, precipitation and isolation.

[0007] For example, after the sulfonation reaction, when sodium hydroxide aqueous solution is used in place of the conventional barium carbonate for neutralization, a large amount of sodium sulfate is deposited, and it takes time for the subsequent filtration. It was confirmed that it is difficult to obtain sodium pentafluorobenzene sulfonate. It was also confirmed that when neutralized with sodium carbonate or its aqueous solution, foaming was severe and jetting from the reactor was possible, and also in this case, a large amount of sodium sulfate was deposited. Further, both sodium hydroxide and sodium carbonate had a problem that heat generation due to neutralization was large and it was difficult to remove heat.

In the present invention, it is considered that the desired pentafluorobenzene sulfonate can be easily isolated and obtained by adding an alkali metal halide or the like without neutralization after the reaction. For comparison, a method for producing sodium benzenesulfonate will be described. In the same manner as in the present invention, sodium benzenesulfonate is produced by sulfonating benzene with fuming sulfuric acid, neutralizing the acid with calcium hydroxide, adding sodium carbonate for salt exchange, removing calcium carbonate by filtration, and concentrating the filtrate. As a result, sodium benzenesulfonate is obtained. In this case, the filtrate must be concentrated and taken out because of the high solubility of sodium benzenesulfonate in water. However, in the pentafluorobenzene sulfonic acids as in the present invention, since hydrogen in the benzene nucleus is replaced with hydrophobic fluorine, it is considered that the hydrophilicity is lower than that of benzene. Therefore, the target pentafluorobenzenesulfonic acid alkali metal salt or pentafluorobenzene sulfonic acid can be obtained by adding an alkali metal halide, an organic alkali metal salt, a quaternary ammonium salt, or an aqueous solution thereof without neutralization after the sulfonation reaction. It is considered that a quaternary ammonium salt of benzenesulfonic acid is precipitated.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The pentafluorobenzene used as a raw material in the present invention is not particularly limited to reagents, industrial products and the like.

The SO ₃ concentration of fuming sulfuric acid used in the present invention is not particularly limited, and 5-65% or 100% sulfur trioxide (sulfuric acid anhydride) can be used.

Here, sulfo of pentafluorobenzene is used.
The conditions for conversion are not particularly limited, and conventional
All you have to do is matter. For example, pentafluorobenzene,
SO _ThreeMix with 1 to 2 mol equivalent of fuming sulfuric acid,
80-120 until the fluorobenzene has completely disappeared
React at 10 ° C for 10-18 hours.

In the present invention, neutralization with an alkaline aqueous solution or a solid base after the sulfonation reaction of pentafluorobenzene is not carried out. In the present invention, after the sulfonation reaction of pentafluorobenzene, at least one selected from the group consisting of an alkali metal halide, an organic alkali metal salt and a quaternary ammonium salt, or an aqueous solution thereof is added.

Here, the alkali metal halide is
It is a salt consisting of an alkali metal of Group 1 and a halogen of Group 17 of the periodic table. That is, it is a salt of a combination of lithium, sodium and potassium with fluorine, chlorine, bromine, iodine and the like. Specifically, sodium chloride, sodium fluoride, sodium bromide, sodium iodide, potassium fluoride, potassium bromide, potassium iodide, lithium chloride,
Lithium bromide and the like.

Also, an alkali metal salt of an organic substance or an aqueous solution thereof can be used. Examples of alkali metal salts of organic substances include, but are not limited to, sodium benzenesulfonate, sodium acetate, potassium acetate, sodium succinate, and sodium oxalate.

On the other hand, examples of the quaternary ammonium salt include, but are not limited to, tetramethylammonium chloride, tetra-n-butylammonium chloride, tricaprylmethylammonium chloride, cetyltrimethylammonium bromide and tetrabutylammonium fluoride. Not something.

In the present invention, one kind or two or more kinds selected from the group consisting of such halides of alkali metals, alkali metal salts of organic substances and quaternary ammonium salts are used in combination.

The amount to be added is 0.3 to 3 parts with respect to pentafluorobenzene in all cases of halides of alkali metals, alkali metal salts of organic substances, and quaternary ammonium salts.
It is 20 times mol, preferably 0.5 to 10 times mol, and these amounts of salts are added as they are or as an aqueous solution containing them.

The conditions for isolating such pentafluorobenzene sulfonate are not particularly limited. For example, the reaction mixture is poured into a mixture of water and ice, and a halide of an alkali metal, an alkali metal salt of an organic compound, A quaternary ammonium salt or the like or an aqueous solution thereof is added to precipitate the objective pentafluorobenzene sulfonate.
The precipitated target crystals can be isolated by filtering, washing the crystals with brine or water, and drying.

[0019]

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

(Example 1) 168 g of pentafluorobenzene was placed in a 500 mL five-necked flask equipped with a stirrer, a thermometer, and a Dimroth condenser, and 25% fuming sulfuric acid 18
9.7 g was added. The mixture was heated and refluxed with stirring in an oil bath. Reflux started at about 83 ° C and the temperature gradually increased to 100 to 110 ° C. Keep that temperature 1
Reaction was carried out for 0 to 12 hours. Then, the reaction solution was cooled to room temperature and poured into 380 g of ice water. When 555 g of saturated saline was added to the solution with stirring, crystals of sodium pentafluorobenzenesulfonate were precipitated. Further, 58 g of sodium chloride was added thereto, stirring was continued to dissolve sodium chloride, the mixture was cooled to 0 ° C., and crystals of sodium pentafluorobenzenesulfonate were separated by filtration. It was washed with 15% saline and dried under reduced pressure.

The amount obtained was 238.6 g, and the pure content yield was 84.7%.

Example 2 A reaction was carried out in the same manner as in Example 1, and the reaction solution was poured into ice water. Instead of saturated saline solution, tetramethylammonium chloride 137g water 30
When 0 mL of the solution was added and the mixture was stirred and cooled, pentafluorobenzenesulfonic acid tetramethylammonium salt was precipitated. The crystals were filtered off.

The yield was 175.9 g, and the pure content yield was 71.5%.

Comparative Example A reaction was carried out in the same manner as in Example 1,
The reaction solution was poured into ice water, and an aqueous sodium hydroxide solution was added for neutralization. However, a large amount of sodium sulfate was deposited, and the intended sodium pentafluorobenzenesulfonate could not be obtained.

[0025]

As described above, according to the present invention,
After the sulfonation reaction, without neutralizing the reaction mixture, an alkali metal halide, an organic alkali metal salt or a quaternary ammonium salt or an aqueous solution thereof is added to precipitate pentafluorobenzenesulfonates, and the mixture is filtered. By doing so, the pentafluorobenzene sulfonates can be obtained without neutralizing the sulfuric acid with a base such as barium carbonate in the reaction solution, and without salt exchange from barium salt or the like. Has the effect.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirotada Iida             1603 Kamiyodenori, Ichikawa-shi, Chiba Toyo Gosei Co., Ltd.             Business F-term (reference) 4H006 AA02 AC61 AD15 BB31 BC50                       BC51 BE43 BE55

Claims (2)

[Claims] 1. A method for producing pentafluorobenzenesulfonates from an aqueous solution of pentafluorobenzenesulfonic acid obtained by sulfonating pentafluorobenzene with fuming sulfuric acid, wherein the reaction mixture is neutralized after the sulfonation reaction. But diluted with water and added with at least one selected from the group consisting of an alkali metal halide, an organic alkali metal salt and a quaternary ammonium salt, or an aqueous solution thereof,
A process for producing pentafluorobenzene sulfonates, which comprises crystallizing, precipitating and isolating pentafluorobenzene sulfonate. 2. The method according to claim 1, wherein the alkali metal halide, organic alkali metal salt or quaternary ammonium salt is added in an amount of 0.3 to 20 times mol relative to the pentafluorobenzene. A method for producing pentafluorobenzene sulfonates.