JPS6035340B2 - Method for producing chlorobenzene sulfochloride - Google Patents

Description

Detailed Description of the Invention The present invention involves adding a reaction product of chlorbenzeso and chlorsulfonic acid to water or dilute sulfuric acid and decomposing excess chlorsulfonic acid to produce chlorbenzeso sulfochloride. It is related to the method, and 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 expelled from the system. After the completion of the decomposition, the sulfuric acid concentration in the sulfuric acid layer is set to 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. After making a solution, it is washed with a small amount of water, and the waste water after washing is used as a water component when decomposing excess chlorosulfonic acid in the reaction product of chlorobenzene and chlorosulfonic acid, and for the same purpose. When producing chlorobenzene sulfochloride, the sulfuric acid layer obtained above is cooled and the precipitate is separated. The present invention relates to a method for producing chlorobenzene sulfochloride, characterized in that the product is reused as a raw material for preparing a reaction product of chlorobenzene and chlorosulfonic acid.

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. When chlorobenzene sulfochloride is produced by the reaction of chlorbesozene and 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 trying 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 reused as recovered hydrochloric acid and recovered sulfuric acid. becomes difficult.

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. .

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 of 360℃ or less, and the generated hydrogen chloride is expelled from the system. Finally, the sulfuric acid concentration in the sulfuric acid layer is
A method of separating aromatic sulfochloride from the sulfuric acid layer after the sulfuric acid concentration is 70% or more (JP 50-100035), or using 20% or more hydrochloric acid instead of dilute sulfuric acid to suppress the dilution heat of sulfuric acid. at a temperature below 35qC, and finally,
By decomposing excess chlorosulfonic acid in a state where the sulfuric acid concentration in the sulfuric acid layer is 70% or more, desorption of hydrogen chloride is caused, and taking advantage of the fact that this desorption reaction is an endothermic reaction, A method for efficiently removing heat (Japanese Unexamined Patent Publication No. 54-55548) has been proposed. However, in the case of chlorobenzene sulfochloride, these methods have a melting point of about 530
0, it becomes a semi-sludgy solid at temperatures below 35 qo, and at high sulfuric acid concentrations of 70% or more, separation by furnace filtration is extremely difficult, and the separated solid components contain a large amount of Since it contains sulfuric acid and unreacted chlorobenzene sulfonic acid, it has drawbacks such as the need for a large amount of cold water to purify the sulfochloride, which is a huge disadvantage from an industrial perspective, and it is difficult to use it. , is the method. With these points in mind, the present inventors investigated the decomposition of chlorobenzene sulfochloride when it was brought into contact with sulfuric acid at various concentrations. I investigated the relationship between rate and temperature.

As a result, when the sulfuric acid concentration was 60 to 90%, the conventional wisdom was that chlorobenzene sulfochloride practically hardly decomposed even at a temperature higher than the melting point of chlorobenzene sulfochloride, for example, 65°C. We discovered a new fact that overcomes the problem, and applied this phenomenon to convert the reaction product of chlorobenzene and chlorosulfonic acid into water, which was measured so that the sulfuric acid concentration in the sulfuric acid layer after the decomposition was 60 to 90%. Alternatively, chlorobenzene sulfochloride is produced by dropping it into dilute sulfuric acid to decompose excess chlorosulfonic acid, and then separating the chlorobenzene sulfochloride layer from the sulfuric acid layer in a liquid state at a temperature of 50 pm or higher. I invented a method to do this and have already filed an application
425 (Special Publication No. 58-34469)). The chlorobenzene sulfochloride layer separated in this manner is sufficiently pure as chlorobenzene sulfochloride as it is, and has a small amount of residual sulfuric acid and chlorobenzene sulfosic acid.

However, when used in precise synthetic reactions, it is necessary to further increase the purity, so the present inventors have developed a method that eliminates the loss of chlorobenzene sulfochloride separated from the sulfuric acid layer. As a result of conducting research on a purification method that does not generate waste products, it was found that the chlorobenzene sulfochloride layer separated from the sulfuric acid layer can be easily purified by simply dissolving it in an inert organic solvent and then washing it with a small amount of water. The total amount of wastewater can be used as the water component when decomposing excess chlorosulfonic acid in the reaction product of chlorobenzene and chlorosulfonic acid, and as the water component when preparing dilute sulfuric acid for the same purpose. He discovered that chlorobenzene sulfochloride could be produced in the same way as when using pure water, and filed an application for an improved invention (Tokuken 1973-
160743 (Special Seki Sho 57-85359)). The method of the improved invention provides a method for producing more purified chlorobenzene sulfochloride, and provides a method that does not generate any waste water in the production of purified chlorobenzene sulfochloride. The inert organic solvent used in the method of the improved invention is a solvent that is sufficiently soluble in chlorobenzene sulfochloride without decomposing it, and is insoluble or soluble in water. For example, aliphatic saturated hydrocarbons, aromatic hydrocarbons,
Halogenated aliphatic hydrocarbons and halogenated aromatic hydrocarbons are used. Specific examples include hexane, heptane, octane, benzene, toluene, xylene, methylene chloride, chloroform, dichloroethane, trichloroethane, chlorobenzene, dichlorobenzene, and the like. In addition, in the above improved invention, the small amount of water used for washing after adding an inert organic solvent to the chlorobenzene sulfonic acid layer to form a solution is the amount of water in the reaction product of chlorobenzene and chlorosulfonic acid. It is necessary that the amount of water be less than or equal to that used to decompose excess chlorosulfonic acid and ultimately bring the sulfuric acid concentration in the sulfuric acid layer to 60-90%.

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 the total amount of chlorobenzene and chlorosulfonic acid, and as a water component when preparing dilute sulfuric acid used for the same purpose. It is possible to reuse it as

Therefore, this purification process does not produce any waste water. The present inventors further improved the methods of the above two applications and conducted research in order to establish a more economical method for producing chlorobenzene sulfochloride IJ. The reactant was added to water or diluted sulfuric acid, hydrogen chloride generated by decomposing excess chlorosulfonic acid was expelled from the system, and the sulfuric acid concentration in the sulfuric acid layer after the decomposition was adjusted to 60 to 90%. At a temperature above, a sulfuric acid layer is formed,
After separating the chlorobenzeso sulfochloride layer in a liquid state, the obtained sulfuric acid layer is cooled to separate a precipitate, and the precipitate is left as is or after co-dehydration with chlorobenzene. They discovered that it could be reused as a raw material for preparing a reaction product with sulfonic acid and completed the present invention. That is, according to the present invention,
■ Most of the precipitate obtained by cooling the sulfuric acid layer is unreacted chlorobenzenesulfonic acid, so it can be reused as a raw material for preparing the reaction product of chlorobenzene and chlorosulfonic acid. By doing so, the yield of chlorbesozene sulfochloride per chlorobenzene used is increased.

■ Since most of the unreacted chlorobenzenesulfonic acid is removed from the sulfuric acid layer, the stringency is improved and the value of the by-product sulfuric acid is improved, and it is also useful for preparing dilute sulfuric acid when decomposing excess chlorosulfonic acid. It becomes possible to reuse it as a raw material.

EXAMPLES Examples and comparative examples will be specifically shown below to explain the present invention, but the present invention is not limited to these examples.

Comparative Example 1 Chlorosulfonic acid 524P (4.5 mol) was charged into a Kolben, and while cooling, chlorobenzene gr (1.5 mol) was added to it.
was added dropwise, and while keeping the internal temperature below 60°C, it took about 3 powders to complete the dropwise addition, and then kept at 6000°C for 2 hours, and then the reaction product was mixed with 488°C of 97% sulfuric acid as a reagent and 300g of pure The mixture was dropped into 60% sulfuric acid 788 solution prepared with water at a temperature of 40 to 60°C over a period of 20 minutes.

After the completion of the dropwise addition, the reaction was aged for 2M at 60 to 6,500 ℃, and dry air was blown into the reaction product for a while to drive the remaining hydrogen chloride out of the system, and the reaction product was transferred to a heat-retaining dropping funnel.
The liquid was separated at ℃. The lower layer is a sulfuric acid layer, and 1100 baits of sulfuric acid with a concentration of 73% were collected. The upper layer was a chlorobenzene sulfochloride layer, and 286 gr of chlorobenzene sulfochloride with a purity of 92% was obtained. The yield based on the charged chlorobenzene was 83%. Next, 210M chlorobenzene was added to the chlorobenzene sulfochloride layer separated from the sulfuric acid layer to form a solution, 120g of pure water was added at room temperature, and the mixture was stirred for 20 minutes, then allowed to rest for 30 minutes, and the aqueous layer was separated. did.

The amount of aqueous layer obtained was 129 mm. From the chlorobenzene layer after separating the aqueous layer, chlorobenzene was distilled off under reduced pressure to obtain 27% of chlorobenzene sulfochloride with a purity of 95%.
I got 7 capitals. Next, the sulfuric acid layer after separating the chlorobenzene sulfochloride layer was cooled to 000, and the deposited precipitate was filtered using a centrifugal filter.

As a result, approximately 1076 sulfuric acid with a concentration of 73% and 24 precipitates were found.
I got a spear. The analysis results of the precipitate (% indicates weight %) were 71.8% chlorobenzenesulfonic acid and 1% sulfuric acid.
The water content was 3.6% and the water content was 14.6%. Example 1 The precipitate obtained in Comparative Example 1 was mixed with 2 whistles (composition: chlorobenzenesulfonic acid 17.0%, ro.089 mol sulfuric acid 3.3%
．． 0.34 moles of water (3.5 moles of water, 0.19 moles of water) and 53 moles of chlorobenzene were charged in a kolben, and chlorobenzene was distilled off under reduced pressure until the boiling point reached 13,000 moles of Hg, and water was co-condensed.

Thereafter, 53% of chlorobenzene was added again, the chicks were dehydrated under the same conditions as before, and the chicks were diluted with 143% of chlorobenzene to obtain a homogeneous solution of 179.7% of chlorobenzenesulfonic acid. Analysis of this homogeneous solution revealed that chlorobenzenesulfonic acid was 18. female r, 0.093 mol sulfuric acid 2.9 diet;
0.030 mol, water 0. Boat, 0.024 mol, chlorobenzene 158. Place X]. It was 407 mol. It can be seen that 0.004 mol of the solvent chlorobenzene was sulfonated by sulfuric acid during the Konada dehydration. The total amount of the homogeneous solution of chlorosulfonic acid (chlorobenzene + chlorosulfonic acid: 1.5 mol) was dissolved in chlorsulfone 524.9 mol.
gr (4.5 mol) under cooling, and the internal temperature was brought to 6.
After completing the dropwise addition over a period of about 3 minutes while keeping the temperature below 0°C, the temperature was kept at 60°C for 2 hours, and then this reaction product was mixed with 639g of sulfuric acid after separating the precipitate obtained in Comparative Example 1. Total amount of water layer after washing obtained in Comparative Example 1: 129
The same procedure as in Comparative Example 1 was carried out except that 60% sulfuric acid was added dropwise to 78% of 60% sulfuric acid prepared with 20 grams of gr and pure water. By separating the sulfuric acid layer and the chlorobenzene sulfochloride layer, 1083 groups of sulfuric acid with a concentration of 74% were recovered from the lower layer.

When the sulfuric acid layer was cooled to 0°C and the precipitate was separated, 36g
047 gr of precipitate [composition (wt%): 69.4% chlorobenzenesulfonic acid, 13.8% sulfuric acid, 16.8% water] and sulfuric acid with a concentration of 75%] was obtained. The upper layer was a chlorobenzene sulfochloride layer, and 290 groups of chlorobenzene sulfochloride layers with a purity of 92% were obtained.

The yield based on the charged chlorobenzene was 90%.
After washing with water, there is a water layer with 12 spots and 95% purity of chlorbenzene sulfochloride. 281 gr of lido was obtained. It can be seen that the yield of chlorobenzene sulfochloride based on the charged chlorobenzene is higher than in Comparative Example 1.

Claims (1)

[Claims] 1 The reaction product of chlorobenzene and chlorosulfonic acid is
Excess chlorosulfonic acid is decomposed by adding it to water or dilute sulfuric acid, the generated hydrogen chloride is expelled from the system, and the sulfuric acid concentration in the sulfuric acid layer after the decomposition is 60 to 90%, and the temperature is 50°C or higher. The chlorobenzene sulfochloride layer is separated in a liquid state from the sulfuric acid layer at a temperature of As a water component when decomposing excess chlorosulfonic acid in the reaction product with chlorosulfonic acid,
By reusing it as a diluent water component when preparing dilute sulfuric acid used for the same purpose, when producing chlorobenzene sulfochloride, the sulfuric acid layer obtained above is cooled and the precipitate is separated. A method for producing chlorobenzene sulfochloride, which comprises reusing the product as a raw material for preparing a reaction product of chlorobenzene and chlorosulfonic acid.