JPH0234928B2 - MMARUKIRUHIDOROKISHIBENZENNOSEIZOHOHO - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a rational and economical method for producing m-alkylhydroxybenzenes. As a method for obtaining substantially pure m-alkylhydroxybenzene from alkylbenzene via alkylbenzene sulfonic acid, for example,
49-33192, JP 49-33193, JP 49-110638
This is a well-known technique described in et al. Their content consists of the following steps: (A) The alkylbenzene sulfonic acid mixture obtained by sulfonating alkylbenzene with sulfuric acid at low temperature is heated in the presence of sulfuric acid at a temperature in the range of 150 to 210°C, or the alkylbenzene is sulfonated with sulfuric acid to a temperature in the range of 150 to 210°C. (B) By maintaining the alkylbenzenesulfonic acid mixture at a temperature of
Preferably, alkylbenzene sulfonic acids other than the m-form are selectively hydrolyzed by contact with water vapor to produce alkylbenzene and sulfuric acid, and the alkylbenzene is azeotroped with water and removed from the system. (C) m-alkylbenzene sulfonic acid that has not undergone hydrolysis is converted into an alkali salt, and then (D) is melted in a caustic manner to obtain m-alkylhydroxybenzene. Generally, when sulfonic acid obtained by sulfonating an aromatic compound with sulfuric acid is causticly melted, the sulfonic acid is converted into an alkali salt, and at the same time, the excessive amount of residual sulfuric acid in the sulfonation reaction solution is removed by an appropriate method. There is. JP-A-49-110638 discloses that sodium hydroxide is added to the sulfonation reaction product until it becomes basic;
The entire amount was not subjected to caustic melting to remove the sulfuric acid content.
As a result, a large amount of sodium sulfate is contained and the viscosity increases during melting, making it impossible to stir.Also, a large amount of sodium sulfate is mixed into the by-product sodium sulfite obtained during post-processing, and the utility value is lost, making it impractical. . In this method, there is a method of separating out the sodium sulfate that precipitates before melting, but it has not been put to practical use because the loss of adhesion of sulfonic acid is large and the steps of washing with water, concentration, refiltration, etc. are complicated and complicated. A commonly used method for separating sulfuric acid is the liming sodation method, in which sulfuric acid is removed as gypsum. However, this method is industrially disadvantageous in terms of process and energy consumption, such as disposal of waste gypsum and concentration of sulfonate aqueous solution. In recent years, a method has been proposed in which alkylbenzenesulfonic acid is extracted with a mixture of a primary to quaternary amine and a water-insoluble organic solvent. (JP 55-154935) This method is also advantageous when recovering dilute organic acids, but
In order to produce alkylhydroxybenzene, a large amount of amine and solvent are required, and in terms of equipment costs, etc.
I can't say it's an advantageous method. The present inventors, while considering methods for overcoming the deficiencies and limitations of previously proposed methods for separating the necessary sulfonic acid and waste sulfuric acid when producing various alkylhydroxybenzenes, It has been found that by adding sodium sulfate (Granite) or acidic sodium sulfate (Gruber's Salt) to a mixture of a specific sulfonic acid and sulfuric acid, the two can be effectively separated into layers and separated advantageously. In other words, in a mixture of o- or p-alkylbenzenesulfonic acid or a mixed sulfonic acid with a high ratio of these and sulfuric acid, even if sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) is added, no layer separation occurs, and m- Sodium sulfate (mirabilite) when the body content exceeds a certain ratio
Alternatively, a layer-splitting effect occurs due to the addition of acidic sodium sulfate (acidic sodium sulfate). It is based on these circumstances that we have arrived at the present invention. In the present invention, alkylbenzenes or alkylbenzene sulfonic acid mixtures are prepared in the presence of sulfuric acid at
After heating at a temperature in the range of 210°C to obtain an alkylbenzenesulfonic acid with a high content of m-isomer and selectively hydrolyzing alkylbenzenesulfonic acids other than m-isomer, sodium sulfate (mirabilite) was added to the hydrolysis reaction solution. Alternatively, a method for producing m-alkylhydroxybenzene is characterized in that acidic sodium sulfate (acidic sodium sulfate) is added and dissolved, and the separated alkylbenzenesulfonic acid layer is separated and causticly melted. Examples of alkylbenzenes suitable for use in the present invention include, for example, toluene, ethylbenzene,
Examples include isopropylbenzene and m-xylene. The reaction of alkylbenzenes with sulfuric acid can be carried out under conditions well known in the art. For example, alkylbenzenes can be prepared by reacting with sulfuric acid at temperatures of 50 to 150°C.
It provides a mixture of alkylbenzenesulfonic acids with high body content. When the alkylbenzene sulfonic acid is heat-treated in the presence of sulfuric acid, preferably at a molar ratio of sulfonic acid and sulfuric acid of about 2:1, at a temperature in the range of 150 to 210°C, preferably 180 to 200°C, the alkylbenzene is produced. Sulfonic acid is isomerized, and the p-form and m-form become equimolar or the content of the m-form increases. Alternatively, alkylbenzene
Even if the reaction is carried out with an excess amount of sulfuric acid at a temperature in the range of 150 to 210 DEG C., a reactant containing about equimolar amounts of p-form and m-form or a high content of m-form is produced. The resulting sulfonation or isomerization reaction mixture is then heated to a temperature in the range of 120 to 180°C, preferably 150 to 170°C.
When water is added or steam distilled at a temperature in the range of °C, p-alkylbenzenesulfonic acid undergoes selective hydrolysis to form alkylbenzene and sulfuric acid, and the alkylbenzene is distilled out of the system azeotropically with water, resulting in additional reused as feedstock for
or used as a starting material. Next, add sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) to the resulting hydrolysis reaction solution.
Add. The amount added is 5 to 20% by weight, preferably 10 to 15% by weight, based on the sulfuric acid in the hydrolysis reaction solution. The addition and dissolution temperature of sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) may be any temperature at which sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) dissolves, but preferably the temperature after hydrolysis is 120°C. ~180℃ is good. When dissolved at high temperature, the reaction solution remains in a high temperature liquid state and separates into two layers: a sulfonic acid layer and a sulfuric acid layer. Stand still 80
Separation is possible at temperatures ranging from ~170°C. Separation efficiency may depend on the amount of sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) added, the meta-isomer content of the reaction solution after hydrolysis, temperature, etc. However, the addition of sodium sulfate or acidic sodium sulfate is an absolute requirement, and without the addition of sodium sulfate or acidic sodium sulfate, the metabody content and temperature will not change. However, it is impossible to separate the sulfonic acid and sulfuric acid layers. When the meta substance content and temperature in the hydrolyzed solution are set to the optimum conditions, if the amount of sodium sulfate (milabilite) or acidic sodium sulfate (acidic sodium sulfate) is 5% by weight or less based on sulfuric acid, sodium sulfate (mirabilite) or The effect of adding acidic sodium sulfate (acidic sodium sulfate) does not appear, and separation of sulfonic acid and sulfuric acid becomes impossible. In addition, if the amount of sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) added is 20% by weight or more based on the sulfuric acid, sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) will not be completely dissolved in the reaction solution. , the separation boundary between the sulfonic acid layer and the sulfuric acid layer becomes unclear, making separation difficult. The amount of sulfonic acid dissolved in the separated sulfuric acid layer is 1% by weight or less, and the sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) dissolved in the same layer precipitates at room temperature and is easily separated. It can be reused next time. The liquid obtained by separately separating sodium sulfate (mirabilite) or acidic sodium sulfate (acidic sodium sulfate) can be used for other purposes as highly concentrated sulfuric acid. After hydrolysis, the alkylbenzene sulfonic acid, which is dissolved by adding sodium sulfate (Sodium sulfate) or acidic sodium sulfate (Sulfur sulfate) and separated into layers, is alkali-chlorinated with, for example, sodium hydroxide under conditions well known in the art. , caustic melting with sodium hydroxide to yield the desired m-alkylhydroxybenzene. The sulfonic acid layer separated from the hydrolysis reaction solution in the method of the present invention is
Since the amount of free sulfuric acid is less than half of that in the case of no separation, the amount of alkali used is reduced when it is made into an alkali salt, which is economically advantageous. In addition, the neutralized sulfonate can be directly melted with caustic material without removing the formed inorganic salt, and even when separating the sulfonate and the formed inorganic salt, since the amount of inorganic salt is small, concentration is required. This method is advantageous compared to other previously known methods because it can be separated very easily without the need for The following examples are preferred specific examples of the present invention, but the present invention is not limited thereto. Example 1 848g of ethylbenzene was placed in a 2L four-necked flask, and 1200g of 98% sulfuric acid was added dropwise with stirring.
It takes time to raise the temperature to 200℃. 4 at a temperature of 200℃
Heat and stir for hours to isomerize. Next, increase the internal temperature to 170℃
The temperature drops until While stirring while maintaining the same temperature,
Hydrolysis is carried out by continuously dropping 1300 ml of water over a period of 15 hours. Subsequently, to the reactant after hydrolysis,
Gradually drop 230 g of a 50% aqueous dispersion of Glauber's salt over 30 minutes. After stirring for 30 minutes while maintaining the temperature at 160°C, the mixture was transferred to a 2L separating funnel, and when left to stand for 30 minutes, it separated into a sulfonic acid layer and a sulfuric acid layer, and 1065 g of the lower sulfuric acid layer was separated. The separated sulfuric acid layer was further cooled with stirring and the precipitated crystals were separated at 25°C, resulting in a transparent 63.2%
Obtained 899 g of concentrated sulfuric acid. Sulfuric acid cut rate is 71%
It is. Add 47% caustic soda to 840 g of sulfonic acid layer, excluding the sulfuric acid layer, until the pH becomes 7.8 to neutralize it, and add the resulting slurry to 563 g of caustic soda, which is heated and melted in a 2L melting pot at a temperature of 330℃. and 83 g of caustic potash mixture. After dropping, check the temperature of the contents.
The temperature was raised from 330°C to 340°C, and the temperature was kept stirring at 340°C for 60 minutes. The resulting molten reaction product is dissolved in 2000 ml of water and neutralized to pH 7.2 with 35% hydrochloric acid. The produced phenols were extracted with ether and distilled to obtain crude ethylphenol. The composition of crude ethylphenol is phenol 2.6
%, cresol 0.5%, o-ethylphenol 0.4
%, m-ethylphenol 93.8%, p-ethylphenol 2.1%, and high boiling content 0.6%. Crude ethylphenol is rectified to obtain a purity of 97.7%.
-307 g of ethylphenol were obtained. The yield is 63% based on consumed ethylbenzene. In addition, in this example, the results of investigating the relationship between the amount of inorganic salt (mirabilite) added to the hydrolysis reaction finished liquid and the sulfuric acid cut rate are shown below.

[Table] Example 2 424 g of ethylbenzene was placed in a 1 L four-necked flask, and while stirring, 600 g of 98% sulfuric acid was added dropwise and the temperature was raised to 200°C over 2 hours. Maintains a temperature of 200℃,
Stir for 4 hours for isomerization. Next, 650 ml of water was added dropwise at 170°C over 15 hours for hydrolysis. reactant
Gradually drop 80g of a 50% aqueous dispersion of Glauber's salt into 850g over 30 minutes. After stirring for 30 minutes, the mixture was allowed to stand at 160°C, and was separated into a 415g sulfonic acid layer and a 500g sulfuric acid layer. The sulfuric acid layer was further cooled to room temperature, and the precipitated crystals were separated to obtain transparent 60.3% concentration sulfuric acid. The sulfonic acid layer was prepared with 490 g of 27% caustic soda solution.
The mixture was neutralized to pH 8.0, heated at 80°C, and 230g of Glauber's salt was collected. The liquid was melted with alkali and post-treated in accordance with Example 1 to yield 4.6% phenol, 1.2% cresol, 0.4% o-ethylphenol, 90.4% m-ethylphenol, and p-ethylphenol.
Crude m-ethylphenol having a composition of 2.3% and a high boiling point of 1.1% was obtained. Next, by fractional distillation, phenol, cresol,
By cutting off the initial distillation of the main component of o-ethylphenol, 150 g of m-ethylphenol with a concentration of 97.5% was obtained. Example 3 503g of toluene was placed in a 1L flask, and while stirring, 1090g of 98% sulfuric acid was added dropwise over 1 hour, and the temperature was raised to 190°C over 2 hours. Isomerization is carried out by stirring at 185-190°C for 4 hours. Next, while maintaining the temperature at 160 to 165°C, 1000 ml of water is continuously added dropwise at a constant rate over a period of 10 hours. Hydrolyzed p-
Toluenesulfonic acid reverts to toluene and sulfuric acid,
Toluene is distilled out of the system by azeotroping with water.
The amount of toluene recovered was 247g. 206 g of a 50% aqueous dispersion of Glauber's sulfate was added dropwise to the hydrolyzed reaction product over 1 hour while stirring. After further stirring at 160°C for 1 hour, the mixture was allowed to stand at 160°C for 30 minutes. Separate 780g sulfonic acid layer and 951g sulfuric acid layer, concentration 58%
of sulfuric acid was obtained. On the other hand, the sulfonic acid layer was subjected to soda treatment, removal of Glauber's salt, and alkali melting and post-treatment in accordance with Example 1 to obtain 198 g of m-cresol with a purity of 98%. Example 4 1,100 g of meta-xylene was placed in a 3-liter flask, and while stirring, 1,700 g of 98% sulfuric acid was added dropwise, and the temperature was raised to 180° C. over 2.5 hours. Insulate at 175-180°C for 3 hours and perform isomerization. Lower the temperature to 150℃ and add 700ml of water.
was continuously added dropwise over 3 hours while maintaining the temperature at 150°C to hydrolyze it. 210 g of a 50% aqueous dispersion of Glauber's sulfate was added to the reaction mixture over a period of 1 hour. After sufficiently dissolving the Glauber's salt, let it stand and form a sulfonic acid layer of 2334g.
760 g of 60% strength sulfuric acid layer was separated. The sulfonic acid layer was converted into soda according to Example 1, cut into sodium sulfate,
Perform alkali melting, neutralization, extraction, and distillation, 3.
714 g of 5-xylenol with a purity of 95% was obtained. Example 5 424 g of ethylbenzene was placed in a 1 L four-neck flask, and while stirring, 600 g of 98% sulfuric acid was added dropwise, and the temperature was raised to 200°C over 2 hours. Maintain the temperature at 200°C and stir for 4 hours for isomerization. Then 650ml at 170℃
of water is added dropwise over a period of 15 hours to hydrolyze. 80 g of a 50% acidic sodium sulfate aqueous dispersion was gradually added dropwise into 850 g of the reactant over 30 minutes. After stirring for 30 minutes, the mixture was allowed to stand at 160°C, and was separated into a 450g sulfonic acid layer and a 450g sulfuric acid layer. The sulfonic acid layer was neutralized to pH 8.0 with a 27% caustic soda solution, filtered while hot at 80°C, and 200g of Glauber's Salt was separated. The filtrate was subjected to alkali melting and post-treatment according to Example 1, and 4.5% phenol and cresol were added to the filtrate.
1.3%, o-ethylphenol 0.4%, m-ethylphenol 90.3%, p-ethylphenol 2.4%,
Crude m-ethylphenol with a high boiling point composition of 1.1% was obtained.
Next, 150 g of 97.5% m-ethylphenol was obtained by fractional distillation to remove the initial distillation of phenol, cresol, and o-ethylphenol as main components.

Claims (1)

[Claims] 1. Alkylbenzene or alkylbenzenesulfonic acid mixture is heated at 150 to 210°C in the presence of sulfuric acid.
After heating at a temperature in the range of , an alkylbenzenesulfonic acid with a high m-isomer content is obtained, and alkylbenzenesulfonic acids other than the m-isomer are selectively hydrolyzed, sodium sulfate is added to the sulfuric acid in the hydrolysis reaction solution. Alternatively, a method for producing m-alkylhydroxybenzene, which comprises adding and dissolving 5 to 20% by weight of acidic sodium sulfate, separating the separated alkylbenzenesulfonic acid layer, and causticly melting the separated alkylbenzenesulfonic acid layer. 2 The process from adding and dissolving the inorganic salt to separating the separated alkylbenzenesulfonic acid layer takes 80~
A manufacturing method according to claim 1, characterized in that it is carried out at a temperature in the range of 180°C. 3. The manufacturing method according to claim 1 or 2, wherein the alkylbenzene of the alkylbenzene and alkylbenzene sulfonic acid mixture is selected from the group consisting of toluene, ethylbenzene, isopropylbenzene, and meta-xylene.