JPS6034946B2 - Method for producing chlorobenzene sulfochloride - Google Patents

Description

Detailed Description of the Invention The present invention produces chlorobenzene sulfochloride by adding a reaction product of chlorobenzene and chlorosulfonic acid to water or dilute sulfuric acid and decomposing excess chlorosulfonic acid. More specifically, the reaction product of chlorobenzene and chlorosulfonic acid is added to water or dilute sulfuric acid to decompose excess chlorosulfonic acid, and the generated hydrogen chloride is removed from the system. After the decomposition, the sulfuric acid concentration in the sulfuric acid layer is 60 to 90%, and the chlorobenzene sulfochloride layer is separated from the sulfuric acid layer in a liquid state at a temperature of 5000°C or more, and an inert organic solvent is added. When producing chlorobenzene sulfochloride, the excess water in the reaction product of chlorobenzene and chlorosulfonic acid is removed by washing the solution with a small amount of water.

As a water component when decomposing rusulfonic acid, and as a dilution water component when preparing dilute sulfuric acid used for the same purpose.
The present invention relates to a method for producing chlorobenzene sulfochloride, which is characterized in that it is reused. Chlorbenzene sulfochloride is generally used as an intermediate in the production of monomers for polymeric compounds, and also as an intermediate in the production of pharmaceuticals and agricultural chemicals.

Chlorobenzene sulfolide is chlorobenzene,
When produced by reaction with chlorosulfonic acid, the reaction formula is shown as follows.

In this reaction, hydrogen chloride gas and sulfuric acid are produced as by-products at the same time as the desired chlorobenzene sulfochloride is produced.Also, since the second stage reaction is an equilibrium reaction, the yield of chlorobenzene sulfochloride is increased. An excess of chlorosulfonic acid is usually used. Therefore, in addition to the sulfochloride and sulfuric acid, the reaction product usually also contains unreacted chlorosulfonic acid and a small amount of chlorobenzenesulfonic acid. To separate sulfochloride from such a reaction product, the reaction product is usually poured into a large amount of cold water or ice water, and unreacted chlorosulfonic acid is decomposed into hydrogen chloride and sulfuric acid. , a method has been adopted in which sulfochloride, which precipitates in cold water, is separated as a solid. However, when attempting to separate sulfochloride by the above method, a large amount of water is used, so the hydrochloric acid and sulfuric acid produced by hydrolysis of chlorosulfonic acid are diluted and cannot be recycled as recovered hydrochloric acid and recovered sulfuric acid. It becomes difficult to use. Therefore, a large amount of waste water is generated, which is economically disadvantageous. Furthermore, when attempting to separate sulfochloride by the above method, heat generated by the hydrolysis reaction of unreacted chlorosulfonic acid and heat of dilution of sulfuric acid generated by hydrolysis of sulfuric acid and chlorosulfonic acid contained in the reaction product are generated. This is said to cause a rapid rise in the temperature of the system, which causes a decomposition reaction of the target sulfochloride, resulting in a decrease in yield. Therefore, when employing the above method, it is generally carried out at a low temperature of about 30°C or less throughout in order to suppress the decomposition reaction of sulfochloride, and the energy required for heat removal is enormous. Become.

In addition, as an improved production method, a reaction product of aromatic hydrocarbons and chlorosulfonic acid is added to dilute sulfuric acid, excess chlorosulfonic acid is decomposed at a temperature below 35:00, and the generated hydrogen chloride is removed from the system. A method of separating aromatic sulfochloride from the sulfuric acid layer after finally increasing the sulfuric acid concentration of the sulfuric acid layer to 70% or more (Japanese Patent Application Laid-open No. 50-100035),
In order to suppress the dilution heat of sulfuric acid, use 20% or more hydrochloric acid instead of dilute sulfuric acid, and at a temperature of 35 qo or less, and in a state where the sulfuric acid concentration in the sulfuric acid layer becomes 70% or more, excessive A method for efficiently removing heat by decomposing chlorosulfonic acid to cause hydrogen chloride to be eliminated, and utilizing the fact that this elimination reaction is an endothermic reaction.
4-555548) and the like have been proposed. but,
In the case of chlorobenzene sulfochloride, these methods have a melting point of about 5yo, so at temperatures below 35yo it becomes a semi-sludgy solid, and at high sulfuric acid concentrations of 70% or more, Separation by filtration is extremely difficult, and since the separated solid component contains a large amount of sulfuric acid and unreacted chlorobenzenesulfonic acid, a large amount of cold water is required to purify the sulfochloride. This method has very large disadvantages and is difficult to adopt from an industrial perspective. With these points in mind, the present inventors investigated the relationship between the decomposition rate of chlorobenzene sulfochloride and temperature when chlorobenzene sulfochloride, which has a melting point of about 53 oo and is solid at room temperature, is brought into contact with sulfuric acid of various concentrations. I looked into it.

As a result, when the sulfuric acid concentration was 60 to 90%, the conventional wisdom that chlorobenzene sulfochloride hardly decomposed even at temperatures above the melting point of chlorobenzene sulfochloride, for example, 6500 ℃, was confirmed. He discovered a new fact that could be used to overcome the problem and filed a patent application (Special Publication No. 55-143425 (Japanese Patent Publication No. 58-134469). The sulfuric acid concentration of the sulfuric acid layer is 60~
After decomposing excess chlorosulfonic acid by dropping it into water or diluted sulfuric acid weighed to 90%, the chlorobenzene sulfochloride layer is separated from the sulfuric acid layer in a liquid state at a temperature of 50 pm or higher. It is called separation. The chlorobenzenesulfochloride layer separated in this way is highly pure as chlorobenzenesulfochloride even as it is, and the amount of residual sulfuric acid and chlorobenzenesulfonic acid is small.

However, when used in precise synthesis reactions, it is necessary to further increase the purity, so the authors of the present invention have developed a method that eliminates the loss of chlorobenzene sulfochloride separated from the sulfuric acid layer and eliminates waste. As a result of conducting research on a purification method that does not release any
It can be easily purified by simply washing with a small amount of water, and the entire amount of waste water after washing can be used as the water component when decomposing excess chlorosulfonic acid in the reaction product of chlorobenzene and chlorosulfonic acid, and for the same purpose. The present inventors have discovered that chlorobenzene sulfochloride can be produced even when used as a water component when preparing dilute sulfuric acid for use in the same way as when pure water is used, and the present invention has been completed. That is, the present invention further advances the technology of the previous application and presents a method for producing more purified chlorobenzene sulfochloride, and a method that does not generate any waste water in the production of purified chlorobenzene sulfochloride. It gives

The inert organic solvent used in the present invention is a solvent that does not decompose chlorobenzene sulfochloride, has sufficient solubility, and is insoluble or sparingly soluble in water.

For example, aliphatic saturated hydrocarbons, aromatic hydrocarbons, halogenated aliphatic hydrocarbons, and halogenated aromatic hydrocarbons are used. Specific examples include hexane, heptane,
Examples include octane, benzene, toluene, xylene, methylene chloride, chloroform, dichloroethane, trichloroethane, chlorobenzene, dichlorobenzene, and the like. Furthermore, in the present invention, the small amount of water used for washing after adding an inert organic solvent to the chlorobenzene sulfochloride layer to form a solution refers to the excess chlorosulfone in the reaction product of chlorobenzene and chlorosulfonic acid. decomposes acid,
It is necessary that the amount of water be equal to or less than the amount of water used to ultimately bring the sulfuric acid concentration in the sulfuric acid layer to 60 to 90%.

With the amount of water under these conditions, it is possible to completely eliminate waste water when obtaining purified chlorobenzene sulfochloride. In other words, the wastewater after washing with water is used as a water component when decomposing excess chlorosulfonic acid in the reaction product of chlorobenzene and chlorosulfonic acid, and as water when preparing dilute sulfuric acid used for the same purpose. It can be reused as a component.

Therefore, this purification process does not produce any waste water. EXAMPLES Examples and reference examples will be specifically shown below to explain the present invention, but the present invention is not limited to these examples. Reference Example 1 524 t (4.5 mol) of chlorsulfonate was charged into a Kolben and 169 t (1.5 mol) of chlorobenzene was added to it while cooling.
5 mol) was added dropwise, and the dropwise addition took about 30 minutes while keeping the internal temperature below 60 q○.After the dropwise addition was completed, the temperature was kept at 60°C for 2 hours.Then, this reaction product was added in 140 tar of pure water at 40~ 60o
The mixture was added dropwise over a period of 20 minutes at a temperature of

After the completion of the addition, the reaction was aged for 20 minutes at 60 to 65°C, and after blowing dry air into the reaction product to drive out the remaining hydrogen chloride, the reaction product was transferred to a heat-retaining dropping funnel and heated at 65°C.
The liquid was separated. The lower layer is a sulfuric acid layer, and approximately 424 tare of sulfuric acid with a concentration of 73% was recovered. The upper layer was a chlorobenzene sulfochloride layer, and chlorobenzene sulfochloride 289 tar with a purity of 90% was obtained. The yield based on the charged chlorobenzene was 82%. Next, 210' of chlorobenzene was added to the chlorobenzene sulfochloride layer separated from the sulfuric acid layer to form a solution, and the mixture was heated to 120 trp at room temperature.
Pure water was added to the mixture, and the mixture was stirred for 20 minutes, then allowed to stand still for 30 minutes, and the aqueous layer was separated.

The amount of aqueous layer obtained was 135 tar. After separating the aqueous layer, chlorobenzene was removed from the chlorobenzene layer under reduced pressure to obtain chlorobenzene sulfochloride with a purity of 95%.
I got 4 tars. Reference Example 2 A reaction product of chlorosulfonic acid and chlorobenzene was prepared using 97% sulfuric acid as a reagent and 300 tar of pure water.
The same procedure as in Reference Example 1 was carried out except that the mixture was added dropwise into 788% sulfuric acid.

By separating the sulfuric acid layer and the chlorobenzene sulfochloride layer, approximately 1100 r of sulfuric acid with a concentration of 73% was recovered from the lower layer. From the upper layer, chlorbenzenesulfocchloride 286tar with a purity of 92% was obtained. Preparation. The yield based on rubenzene was 83%. After washing with water, an aqueous layer of 129 tar and 277 tar of chlorobenzene sulfochloride with a purity of 95% were obtained. Example 1 A reference example of the reaction product of chlorosulfonic acid and chlorobenzene -
The total amount of the water layer after washing obtained in step 1 was 135 ta r and pure water 20
The same procedure as in Reference Example 1 was carried out except that the mixture was dropped into the water component 1559r mixed with tar.

By separating the sulfuric acid layer and the chlorobenzene sulfochloride layer, approximately 450 trr of sulfuric acid with a concentration of 73% is extracted from the lower layer.
I was able to recover it. Chlorobenzene sulfochloride 304 with a purity of 85% was obtained from the upper layer. The yield based on the charged chlorobenzene was 82%. After washing with water, 1509r
aqueous layer and 95% purity chlorobenzene sulfochloride 2
74 tar was obtained. In comparison with Reference Example 1, in order to decompose excess chlorosulfonic acid, this reference example 1 was used instead of pure water.
Even if the water component after washing with water is used, the purity and yield of purified chlorobenzene sulfochloride do not change at all. Example 2 The reaction product of chlorosulfonic acid and chlorobenzene was added to the reagent 9.
60% sulfuric acid prepared with 488 t r of 7% sulfuric acid, the total amount of 135 t r of the aqueous layer obtained in Reference Example-1, and 180 t r of pure water.
The same procedure as in Reference Example 11 was carried out except that the mixture was dropped into the 03 tank.

By separating the sulfuric acid layer and the chlorobenzene sulfochloride layer, approximately 1115 sulfuric acid with a concentration of 73% is extracted from the lower layer.
Chlorobenzene sulfochloride 286% with a purity of 92% was obtained from the upper layer from which the tar was recovered. The yield based on the charged chlorobenzene was 83%. After washing with water, 129%
aqueous layer and 95% purity chlorobenzene sulfochloride 2
77 tar was obtained. In comparison with Reference Example 2, the purity of purified chlorobenzene sulfochloride was also improved by using 60% sulfuric acid using the water component after washing with water in Reference Example 1 instead of pure water to decompose excess cross-sulfonic acid. , the yield does not change at all.

Example-3 Except that the chlorobenzene sulfochloride layer separated from the sulfuric acid layer was made into a solution with 210% dichloroethane.
Everything was carried out in the same manner as in Example-2.

Claims (1)

[Claims] 1 The reaction product of chlorobenzene and chlorosulfonic acid is
Excess chlorsulfonic acid is decomposed by adding it to water or dilute sulfuric acid, the generated hydrogen chloride is expelled from the system, the sulfuric acid concentration in the sulfuric acid layer after the decomposition is 60 to 90%, and the temperature is increased to 50°C or higher. When producing chlorobenzene sulfochloride by separating the chlorobenzene sulfochloride layer in a liquid state from the sulfuric acid layer at temperature, adding an inert organic solvent to make a solution, and washing with a small amount of water, The waste water after the water washing is used as a water component when decomposing excess chlorosulfonic acid in the reaction product of chlorobenzene and chlorosulfonic acid,
Further, a method for producing chlorobenzene sulfochloride, which is characterized in that it is reused as a dilution water component when preparing dilute sulfuric acid used for the same purpose.