JPS6116386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing diarylsulfones.

More specifically, it relates to a method for producing diarylsulfone, which is characterized by reacting aromatic sulfonic acid and aromatic hydrocarbon in the coexistence of perfluorosulfonic acid type resin (hereinafter referred to as super acidic type resin). be. Diarylsulfone generally has excellent heat resistance and is a compound useful as a raw material for various heat-resistant resins and as a resin stabilizer.

Conventionally, methods for producing diarylsulfones include (1) performing a Friedel-Crafts reaction between an aromatic sulfochloride and an aromatic hydrocarbon under a Lewis acid catalyst such as anhydrous aluminum chloride or anhydrous ferric chloride; [FR Jensen, G.
Goldman “Friedel Crafts and Releted
Reactions”Vol., P1319, ed.by GAOlah,
John Wiley (1964)], (2) Method of reacting aromatic sulfochloride and aromatic hydrocarbon in the coexistence of aromatic sulfonic acid (German Patent No. 1950394), (3)
A method of reacting aromatic sulfonic acid and aromatic hydrocarbon in the presence of a phosphorus oxide-based dehydrating agent (Japanese Patent Publication No. 1973-
24662), (4) A method of reacting aromatic hydrocarbons with a mixture of sulfuric anhydride and dimethyl sulfate (methyl pyrosulfate) (British Patent No. 895464 and Japanese Patent Publication No. 1983-
11817), (5) 4-chlorobenzene sulfonic acid and chlorobenzene at a temperature of 220 to 260°C for 30 to
A method of reacting by maintaining the pressure above atmospheric pressure of 1100KN/m ² (Japanese Patent Application Laid-open No. 76834/1989), (6) Reacting aromatic sulfochloride and aromatic hydrocarbon in the coexistence of a sulfone-type ion exchange resin. Method (Unexamined Japanese Patent Publication 1973-
No. 53345) are known.

However, in method (1), equimolar Lewis acid catalyst is required for aromatic sulfochloride, separation of the catalyst is complicated, cannot be reused, and requires equipment that is resistant to corrosion. In method (2), aromatic sulfonic acid is required in an equimolar amount to aromatic sulfochloride, recovery of aromatic sulfonic acid is complicated, and moreover, it is generally recovered as a hydrate. , a dehydration step is also required for reuse. In method (3), the dehydrating agent is usually required in an amount of 0.5 to 1.0 mol based on the aromatic sulfonic acid.
In addition, method (4) uses a large amount of highly toxic dimethyl sulfate, which increases the burden of waste liquid treatment and other pollution-free processes.Method (5) uses extremely high temperature and pressure conditions. In method (6), which requires a high-pressure device, the ion-exchange resin has disadvantages such as desulfonation of the resin at temperatures above 170°C, making it unsuitable for reuse. There is.

As a result of intensive studies aimed at providing an industrially advantageous method for producing diarylsulfone, the present inventors have discovered that aromatic sulfonic acid and aromatic hydrocarbon are reacted in the presence of a super acidic resin. The present invention was achieved by discovering that diarylsulfone can be produced extremely easily by this method.

The method of the present invention is completely unknown heretofore. As mentioned above, the production of diaryl sulfone by reacting aromatic sulfonic acid with aromatic hydrocarbons can only be achieved using a strong dehydrating agent and a dehydration reaction at high temperature and high pressure. .

On the other hand, method (6) above is known as a method for producing diarylsulfone using a sulfonic acid type ion exchange resin, but in this method, aromatic sulfochloride is used as a raw material and reacted with an aromatic hydrocarbon. . However, if aromatic sulfonic acid is used as a raw material, diarylsulfone cannot be produced by a method using a sulfonic acid type ion exchange resin.

The method of the present invention provides an industrially useful method for producing diarylsulfone using aromatic sulfonic acid as a raw material, and involves combining aromatic sulfonic acid and aromatic hydrocarbon in the presence of a super acidic resin. When reacted, diarylsulfone can be produced in high yield, and the superacidic resin is removed from the reaction mixture by a filtration operation, which can be used as it is for the next reaction. Therefore, in the method of the present invention, there is no loss of resin and diarylsulfone can be produced very easily.

Aromatic sulfonic acids used in the process of the invention include benzenesulfonic acid, O- and P-
toluenesulfonic acid, O- and P-ethylbenzenesulfonic acid, 2,4-, 2,5- and 3,
5 xylene sulfonic acid, 2,4,5-, 2,4,
6- and 3,4,5-trimethylbenzenesulfonic acid, P-methoxybenzenesulfonic acid, O-
and P-chlorobenzenesulfonic acid, O- and P-bromobenzenesulfonic acid, 2,4-dichlorobenzenesulfonic acid, m- and P-nitrobenzenesulfonic acid, naphthalenesulfonic acid, and the like.

Aromatic hydrocarbons used in the method of the invention include benzene, toluene, ethylbenzene, xylene, trimethylbenzene, chlorobenzene,
Examples include bromobenzene, anisole, naphthalene, biphenyl, diphenyl ether, and the like.

The superacidic resin used in the method of the present invention is a perfluorosulfonic acid type resin (Nafion H: Du'pont) consisting of a copolymer of sulfonyl fluoride vinyl ether and tetrafluoroethylene. Until now, sulfonic acid type ion exchange resins (obtained by sulfonating polymers or copolymers of aromatic vinyl compounds) have generally been used.
Although it decomposes at temperatures above 140°C, this super acidic resin (Nafion H) has the characteristic of being heat resistant at temperatures of 200°C and above.

In the method of the present invention, the aromatic hydrocarbon is usually used in an amount of 1.0 to 20 mol, preferably about 1.0 to 10.0 mol, per 1.0 mol of aromatic sulfonic acid. In addition, the super acidic resin (Nafion H) is
It is used in an amount of 1 to 500% by weight, preferably about 5 to 300% by weight, based on the aromatic sulfonic acid.

However, the amount of superacidic resin is not limited to the above amount, and should be determined in consideration of yield and economical efficiency.

The reaction temperature is generally 80-200°C. The method of the present invention is generally carried out by heating the aromatic sulfonic acid, aromatic hydrocarbon, and superacidic resin while stirring, and removing the water produced. The reaction time is usually completed in 10 to 50 hours. After the reaction is completed, the superacidic resin is removed by filtration, washed with the aromatic hydrocarbon used, dried, and can be used in the next reaction.

The filtration and washing liquids are combined, washed with water and then distilled or directly steam distilled to obtain the diarylsulfone.

Diarylsulfones obtained by the method of the present invention include diphenylsulfone, 4-methyldiphenylsulfone, 4,4'-dimethylsulfone, 2,4'-dimethylsulfone, 2,4,4'-trimethyldiphenylsulfone. enyl sulfone, 2,4,6-trimethyl-4'-chlorodiphenyl sulfone, 4-chlorodiphenyl sulfone, 4-bromodiphenyl sulfone, 4,4'-dichlorodiphenyl sulfone, 4,4'-dibromodif enylsulfone, 4-
Chloro-4'-methyldiphenyl sulfone, 2,
4,4'-trichlorodiphenylsulfone, 4-methoxydiphenylsulfone, 4-methoxy-4'-
Chlorodiphenylsulfone, 4-methyl-4'-methoxydiphenylsulfone, 4-nitrodiphenylsulfone, 4-chloro-4'-nitrodiphenylsulfone, 2-t-butyl-4'-chlorophenylsulfone, 4 -phenoxy-diphenylsulfone, 4-phenylsulfone, and the like.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Preparation of super acidic resin (perfluorosulfonic acid resin) 50 g of potassium perfluorosulfonate resin (trade name: Nafion Du'pont) was stirred with 40 ml of 4N hydrochloric acid at room temperature for 4 hours. and washed with distilled water until neutral. Repeat this operation 4 more times
After repeating this process several times, it was dried at 80 to 90°C under a reduced pressure of 10 mmHg to obtain a perfluorosulfonic acid type resin.

Example 1 14.4 g (0.18 mol) of anhydrous sulfuric acid is added dropwise to 31.2 g (0.4 mol) of benzene at an internal temperature of 25° C. or less over 30 minutes. Further, after stirring at 50° C. for 1 hour, 8.5 g of the perfluorosulfonic acid type resin prepared above (hereinafter simply referred to as perfluorosulfonic acid type resin) is added, and stirring is continued while refluxing. After about 8 hours, the temperature of the reaction mixture gradually increases. 140～
Cook for a further 10 hours, maintaining the temperature at 150°C. During this time, the water distilled out together with benzene was separated in a water separator, and the benzene was recycled into the flask. After cooling to 70°C, add about 10 ml of benzene, separate the perfluorosulfonic acid type resin at 50°C, and wash with a small amount of benzene. After combining the solution and the washing solution, benzene was removed by azeotropic distillation while adding water, and a precipitate was obtained. After filtering, washing with water, and drying, diphenyl sulfone was obtained.

Yield: 30.8g, yield relative to sulfuric anhydride: 78.5%,
Melting point 122-125℃. A pure product was obtained by recrystallization from water-ethanol. Melting point 127-128℃.

Example 2 15.8 g (0.1 mol) of benzenesulfonic acid, 11.7 g (0.15 mol) of benzene, and 4.7 g of perfluorosulfonic acid type resin were heated and stirred under reflux. After about 7 hours, the reaction mixture gradually rises. 140~150℃
Cook for a further 10 hours, maintaining the temperature at . Meanwhile, the water distilled out with benzene was separated in a water separator, and the benzene was circulated into the flask.
Diphenyl sulfone was obtained by processing in the same manner as in Example 1.

Yield 16.8g (yield 77.0%). Melting point 123-125℃.

Example 3 19.2 g (0.1 mol) of P-chlorobenzenesulfonic acid, 67.5 g (0.6 mol) of chlorobenzene, and 19.2 g of perfluorosulfonic acid type resin were heated and stirred under reflux for 20 hours. At this time, the water distilled out together with chlorobenzene was separated in a water separator, and the chlorobenzene was circulated into the flask.

After cooling to 70°C, the perfluorosulfonic acid type resin was separated and washed with a small amount of chlorobenzene. The liquid and washing liquid were combined and steam distilled to yield 4,4'-dichlorodiphenyl sulfone.

Yield 21.5g (yield 75%), melting point 146-148℃, water-
A pure product was obtained by recrystallization from ethanol. Melting point 148
~149℃.

Example 4 The same operation as in Example 3 was carried out using 19.2 g (0.1 mol) of P-chlorobenzenesulfonic acid and 67.5 g (0.6 mol) of chlorobenzene based on the total amount of perfluorosulfonic acid type resin used in Example 3. do the
4,4'-dichlorodiphenyl sulfone was obtained.

Yield 21.2g (yield 73.8%). Melting point 146-148℃.

Example 5 18.8 g (0.1 mol) of P-methoxybenzenesulfonic acid, 92 g (1.0 mol) of toluene, and 37.6 g of perfluorosulfonic acid type resin were heated and stirred under reflux for 24 hours. At this time, water distilled out together with toluene was separated in a water separator, and the toluene was circulated into the flask. After cooling to 70°C, the perfluorosulfonic acid type resin was separated and washed with a small amount of toluene. When the liquid and the washing liquid are combined and toluene is removed by azeotropic distillation while adding water, 4-
Methyl-4'-methoxydiphenyl sulfone was obtained.

Yield 19.8g (yield 76.1%), melting point 99-101°C. A pure product was obtained by recrystallization from water-ethanol. melting point
104-105℃.

Example 6 P-toluenesulfonic acid 17.2 g (0.1 mol) P-
90 g (0.8 mol) of chlorobenzene and 17.2 g of perfluorosulfonic acid type resin were heated and stirred under reflux for 25 hours. At this time, the water distilled out together with chlorobenzene was separated in a water separator, and the chlorobenzene was circulated into the flask. After cooling to 70°C, the perfluorosulfonic acid type resin was separated and washed with a small amount of chlorobenzene. The solution and washing solution were combined and steam distilled to yield 4-chloro-4'-methyldiphenylsulfone.

A pure product was obtained by recrystallization from ethanol, yield 19.7 g (yield 74%), melting point 120-121°C. Melting point 124-125
℃.

Example 7 Example 6 was carried out using 20.3 g (0.1 mol) of m-nitrobenzenesulfonic acid, 90 g (0.8 mol) of chlorobenzene, and 20.3 g of perfluorosulfonic acid type resin.
3-nitro-4'-chlorodiphenylsulfone was obtained by the same procedure as above.

A pure product was obtained by recrystallization from acetic acid, yield: 23.5 g (79.1%), melting point: 135-136°C. Melting point 138-139℃.

Claims (1)

[Claims] 1. A method for producing diarylsulfone, which comprises reacting an aromatic sulfonic acid and an aromatic hydrocarbon in the presence of a perfluorosulfonic acid type resin.