JPS6215071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing 1-amino-4-bromoanthraquinone-2-sulfonic acid or a salt thereof. More specifically, the present invention involves brominating 1-aminoanthraquinone-2-sulfonic acid in the presence of sulfuric acid in the presence or absence of an inert organic solvent, and then reacting it in the presence of an inert organic solvent. By adding water and adjusting the sulfuric acid concentration of the mixture to 7% or more and the specific gravity of sulfuric acid to be lower than the specific gravity of the inert organic solvent, only sulfuric acid is extracted into the aqueous layer, and the organic solvent containing the brominated product is extracted. Add water to the solvent layer,
1-amino-4-, which is characterized by extracting poorly water-soluble impurities into an organic solvent layer and obtaining the target product from the aqueous layer.
This is a method for producing bromoanthraquinone-2-sulfonic acid or a salt thereof.

1-Amino-4-bromoanthraquinone-2-
Sulfonic acid (hereinafter referred to as bromamic acid) is an important intermediate for anthraquinone dyes, and is obtained by bromination of 1-aminoanthraquinone-2-sulfonic acid. At this time, 1-amino-2.
4-dibromoanthraquinone, 1-amino-2-
In order to suppress bromoanthraquinone, 1-amino-4-bromoanthraquinone, etc. (hereinafter referred to as by-products), 1-aminoanthraquinone-2-sulfonic acid is salted out or neutralized in water to produce 1-aminoanthraquinone-2. - Many methods are known for carrying out the bromination in the form of fine crystals of alkali metal salts of sulfonic acids. However, even with improved methods (e.g. West German Patent No. 2303746, Czechoslovakia Patent No. 169459), the crystalline form of the alkali metal salt of 1-aminoanthraquinone-2-sulfonic acid is not suitable (if not thin needle-like crystals). ), or if the mixing during bromination is insufficient, a large amount of starting material remains and the yield of the target product decreases.

In order to overcome the above drawbacks, a method has been developed in which 1-aminoanthraquinone-2-sulfonic acid is brominated in concentrated sulfuric acid. (Ciekoslovakia Patent No. 122317, Japanese Patent Application Laid-Open No. 1983-48749, etc.) However,
These methods also generate by-products, so a step for removing them is necessary, and the following methods are used.

(1) A method in which the reaction mixture is diluted with a large excess of water and poorly water-soluble by-products are removed by filtration or organic solvent extraction, or a combination of both (Japanese Patent Publication No. 30510/1983).

(2) Dilute the reaction mixture with water and adjust the sulfuric acid concentration to 60-85
% to precipitate bromamic acid and release by-products into the liquid (Japanese Patent Application Laid-Open No. 54-48747-9)
issue).

(3) After diluting the reaction mixture with water to which an appropriate inorganic salt has been added and separating the precipitated crystals, the cake is redissolved in a large amount of water and the by-products are removed in the same manner as in (1) above (Unexamined Japanese Patent Publication No. (Sho 54-48747).

Using bromamic acid, which contains by-products, as an intermediate for dye synthesis may lead to a decrease in quality (for example, a change in hue or a decrease in concentration) depending on the dye, so it is necessary to remove by-products as much as possible. . In this sense, the method (2) above not only has an insufficient effect of removing by-products (the product contains at least 0.4% of by-products), but also causes a lot of loss of the target product.

On the other hand, the organic solvent extraction method described in (1) above has high removal efficiency of by-products (the amount of by-products in the product can easily be 0.2% or less), and there is almost no loss of the target product (2).
It is better than the method. However, in method (1), it is necessary to completely dissolve the bromamic acid.
Therefore, dilution with a large excess of water results in an enormous amount of processing liquid, which is not economical.

Method (3) is not industrially advantageous because the process is complicated.

The inventors of the present invention have conducted extensive studies in order to reduce the amount of processing liquid as much as possible. In the process, we focused on the fact that bromamic acid (free acid) precipitates out in the presence of sulfuric acid and its solubility decreases, and we investigated a method for selectively removing sulfuric acid from the system. When water is added in the presence of an active organic solvent, it is surprising that within a specific sulfuric acid concentration range, bromamic acid partitions almost completely into the organic solvent layer as free acid crystals and is easily separated from the aqueous layer containing sulfuric acid. Heading Completing the Invention.

The bromination of the present invention can be carried out, for example, by the following method.

(1) A method of brominating 1-aminoanthraquinone-2-sulfonic acid in the presence of sulfuric acid. (Ciekoslovakia Patent No. 122317) (2) A method of brominating 1-aminoanthraquinone-2-sulfonic acid in an organic solvent in the presence of sulfuric acid.

(3) A method in which 1-aminoanthraquinone is sulfonated with sulfuric acid or chlorosulfonic acid in the presence of an inert organic solvent, and then brominated in the presence of sulfuric acid without isolation.

(4) A method of extracting the sulfonated mixture of (3) with sulfuric acid and brominating the extract. (Japanese Patent Publication No. 54-30510) (5) A method of sulfonating 1-aminoanthraquinone with sulfuric acid or fuming sulfuric acid, and then brominating it in sulfuric acid (Japanese Patent Publication No. 54-48749) (6) Sulfonation of (5) A method in which the mixture is subsequently brominated in the presence of sulfuric acid in the presence of an inert organic solvent.

In the present invention, the inert organic solvent added to the bromination reaction mixture does not necessarily need to be added when the required amount is used in the bromination, but it may be necessary to add some or all of it when it is not used. be. Examples of such inert organic solvents include halogenated hydrocarbons such as monochlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and 1,3,5-trichlorobenzene, and tetrachloroethane. , aliphatic halogenated hydrocarbons such as tetrochlorethylene,
and nitrobenzene. Industrially, 1,2-dichlorobenzene and trichlorobenzene are preferably used. The amount used is determined from the solubility of the by-product in those solvents. It is usually 20 to 150 times the weight of the by-product in the reaction mixture.
The larger the amount used, the higher the removal efficiency of by-products. When bromination is carried out in the presence of an organic solvent, it is not necessary to add a new organic solvent.

In the present invention, when adding an inert organic solvent to the bromination reaction mixture, it is added before the addition of water, or
Alternatively, it may be added after the addition of water, or at the same time as the water.

The amount of water used to remove sulfuric acid from the reaction mixture is set so that the specific gravity of sulfuric acid after dilution with water is smaller than the specific gravity of the organic solvent. For example, as an inert organic solvent, 1,2-dichlorobenzene (25℃
1.30), the sulfuric acid concentration is set to 40% or less, preferably 35% or less. The lower limit of the sulfuric acid concentration is determined by the solubility of bromamic acid, and is usually 7% or more, preferably 15% or more.

There are no particular restrictions on the temperature when adding water, but usually
The temperature is 20-90℃. When a large amount of sulfuric acid is used during bromination and water is added to a reaction mixture in which bromamic acid is dissolved, the temperature is preferably 50 to 90°C in order to obtain good crystals (crystals that tend to settle). sometimes 90℃
Higher temperatures may be preferred in some cases.

When the sulfuric acid concentration is in the above range in this manner, the bromamic acid crystals are almost completely distributed and precipitated in the organic solvent layer (lower layer). The aqueous layer (upper layer) containing sulfuric acid can be easily separated using conventional clarification methods. The concentration of bromamic acid that partitions into the aqueous layer is usually
It is less than 500mg/, which is not a serious problem.
After decolorizing the aqueous layer if necessary, it can be reused as it is as dilute sulfuric acid or after being concentrated. Performing the separation operation several times within the above sulfuric acid concentration range increases the efficiency of sulfuric acid removal.
Alternatively, it can be carried out continuously using a centrifugal sedimentation device or the like.

In this way, the sulfuric acid remaining in the organic solvent layer is
The molar ratio to bromamic acid can be 3 or less. Therefore, the amount of water required for the subsequent dilution is sufficient to be 20 times or less by weight, usually 5 to 20 times, preferably 5 to 12 times by weight, relative to the bromamic acid. In order to promote dissolution of bromamic acid, the dissolution temperature is preferably 60 to 120°C. Treating the solution with activated carbon and/or diatomaceous earth is advantageous in improving liquid separation properties. It is also advantageous to perform the extraction operation in multiple stages to ensure complete removal of by-products.

A method known per se is used to obtain the target product from the aqueous layer after extraction of the by-product. That is, an alkali metal hydroxide is added to adjust the salt concentration to an appropriate level, and the alkali metal salt of bromamic acid is precipitated and separated. Since the sulfuric acid content has already been sufficiently removed, the amount of inorganic salts or sulfuric acid contained in the cake is small, and in particular, if the cake is neutralized and salted out to near neutrality, a product with a low inorganic salt content can be obtained without washing the cake. I can do it. In this way, a highly purified target product containing almost no by-products can be obtained.

The method of the present invention is not only economically advantageous in that the amount of treatment liquid required is much smaller than that of the known method (more than 25 times the weight of bromamic acid), but also the sulfuric acid used for bromination can be recovered without waste. and the purity of the resulting product is high. Therefore, the industrial value of the present invention is high.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 1-aminoanthraquinone in 157 parts of 100% sulfuric acid
32.2 parts of 2-sulfonic acid (purity 94%) was charged, and the temperature was raised to 98°C while stirring thoroughly. Next, 14.4 parts of bromine was added dropwise over 3 hours at the same temperature, and the mixture was further stirred at the same temperature for 3 hours. Chromatography showed that most of the starting material had disappeared.

After removing excess bromine under reduced pressure, 62 parts of 1,2-dichlorobenzene was added to the reaction mixture, and 6.28 parts of water was added dropwise at 60° C. over 2 hours with gentle stirring. After cooling to 30°C, the mixture was allowed to stand to separate into two layers, and 763 parts of the upper layer (aqueous layer) was separated. This contained 137 parts of sulfuric acid.

Next, 370 parts of water, 0.2 parts of activated carbon, and 1.2 parts of diatomaceous earth were added to the organic solvent layer, heated at 90-95°C for 2 hours, heated, and then separated to form a 1,2-dichlorobenzene layer of 63.2 parts. Obtained. 36 parts of 45% sodium hydroxide was added dropwise to the aqueous layer at 85°C, cooled to 30°C, separated, and dried to obtain 40.1 parts of orange crystals. The results of compositional analysis were as follows.

1-amino-4-bromanthraquinone-2-sulfonic acid 89.4% 1-aminoanthraquinone-2-sulfonic acid
0.3% Byproduct 0.1% 1-amino-4-bromanthraquinone-2-
The yield of sulfonic acid was 94%.

Example 2 120 parts of 1,2-dichlorobenzene was added to the reaction mixture obtained by bromination in the same manner as in Example 1, and 366 parts of water was added at 85°C with gentle stirring for 4 hours. dripped. After cooling to 40°C, the mixture was allowed to stand to separate into two layers, and 392 parts of the aqueous layer was separated.
This contained 98 parts of sulfuric acid. more water 236
1 part was added, stirred and left to stand, and 276 parts of the aqueous layer was separated. This contained 44.2 parts of sulfuric acid.

Next, 250 parts of water was added to the organic solvent layer, and Example 1
Activated carbon treatment, filtration, liquid separation, and salting out were performed in the same manner as above to obtain 39.0 parts of the desired product. The results of compositional analysis were as follows.

1-Amino-4-bromoanthraquinone-2-sulfonic acid 91.9% 1-aminoanthraquinone-2-sulfonic acid
0.3% Byproduct 0.05% 1-amino-4-bromanthraquinone-2-
The yield of sulfonic acid was 94%.

Example 3 70 parts of trichlorobenzene was added to the reaction mixture obtained by bromination in the same manner as in Example 1, and the mixture was heated at 65°C.
628 parts of water was slowly added dropwise over 2 hours with stirring. After cooling to 30°C, the mixture was allowed to stand to separate into two layers, and 720 parts of the aqueous layer was separated. This contained 128 parts of sulfuric acid.

Next, 370 parts of water, 0.2 parts of activated carbon, and 1.2 parts of diatomaceous earth were added to the organic solvent layer, heated at 90-95°C for 4 hours, heated, and then separated to obtain 71.2 parts of trichlorobenzene layer. The aqueous layer was salted out in the same manner as in Example 1,
40.1 parts of the target product was obtained. The results of compositional analysis were as follows.

1-amino-4-bromanthraquinone-2-sulfonic acid 89.4% 1-aminoanthraquinone-2-sulfonic acid
0.3% By-product 0.08% Example 4 120 parts of 1,2-dichlorobenzene and 32.2 parts of 1-aminoanthraquinone-2-sulfonic acid with a purity of 94%
55.0 parts of 98% sulfuric acid was added dropwise at 70°C over 1 hour while thoroughly stirring. The temperature was then raised to 98°C, 14.4 parts of bromine was added dropwise over 4 hours, and the mixture was kept at the same temperature for an additional 10 hours. According to chromatography, the bromination reaction was complete.

After removing excess bromine under reduced pressure, 50%
Water containing 1.1 parts of sodium bisulfite at °C
128 parts were added dropwise over 1 hour. The mixture was then allowed to stand still to separate into two layers, and 60 parts of the aqueous layer was collected. This contained 14.4 parts of sulfuric acid. Furthermore, 55.4 parts of water was added and a stirring device was used to separate 107.5 parts of the aqueous layer. This contained 18.2 parts of sulfuric acid.

Next, 284 parts of water was added to the organic solvent layer, and the mixture was treated with activated carbon, filtered, separated, and salted out in the same manner as in Example 1 to obtain 39.9 parts of the desired product. The results of compositional analysis were as follows.

1-Amino-4-bromanthraquinone-2-sulfonic acid 89.8% 1-aminoanthraquinone-2-sulfonic acid
0.4% Byproduct 0.08% 1-amino-4-bromanthraquinone-2-
The yield of sulfonic acid was 94%.

Example 5 24.2 parts of 1-aminoanthraquinone with a purity of 96% was added to 300 parts of 1,2-dichlorobenzene, and 11.1 parts of 98% sulfuric acid was added dropwise at 100° C. with thorough stirring. Next, the temperature was raised to 180°C and kept at the same temperature for 10 hours. During this time, 1,2-dichlorobenzene was refluxed, and water produced by the sulfonation reaction was condensed in the middle of the 1,2-dichlorobenzene reflux system, separated and extracted. After the reaction was completed, the mixture was cooled to 95° C., 54 parts of 4% fuming sulfuric acid was added, and the mixture was allowed to stand for liquid separation to extract 150 parts of a 1,2-dichlorobenzene layer. Then, 14.4 parts of bromine was added dropwise over 20 hours at a temperature in the range of 95 to 98°C while stirring. According to chromatography, the bromination reaction was complete.

After removing excess bromine under reduced pressure, 50%
Water containing 1.1 parts of sodium bisulfite at °C
128 parts were added dropwise over 1 hour. The mixture was then allowed to stand still to separate into two layers, and 58 parts of the aqueous layer was collected. Further, 56 parts of water was added, and the mixture was stirred and allowed to stand, and 105 parts of the water layer was separated.

Next, 284 parts of water was added to the organic solvent layer, and Example 1
Activated carbon treatment, heating, liquid separation, and salting out were performed in the same manner as above to obtain 40.0 parts of the desired product. The results of compositional analysis were as follows.

1-Amino-4-bromanthraquinone-2-sulfonic acid 89.6% 1-aminoanthraquinone-2-sulfonic acid
0.3% Byproduct 0.1% 1-amino-4-bromanthraquinone-2-
The yield of sulfonic acid was 90% based on 1-aminoanthraquinone.

Claims (1)

[Claims] 1. After brominating 1-aminoanthraquinone-2-sulfonic acid in the presence of sulfuric acid in the presence or absence of an inert organic solvent, the reaction mixture is prepared in the presence of an inert organic solvent. By adding water to adjust the sulfuric acid concentration to 7% or more and the specific gravity of sulfuric acid to be lower than the specific gravity of the inert organic solvent, only sulfuric acid is extracted into the aqueous layer, and the organic solvent containing the brominated product is extracted. 1-, which is characterized by adding water to the layer, extracting poorly water-soluble impurities into the organic solvent layer, and obtaining the target product from the aqueous layer.
A method for producing amino-4-bromanthraquinone-2-sulfonic acid or a salt thereof. 2 1-Aminoanthraquinone-2 is produced by reacting 1-aminoanthraquinone with sulfuric acid or chlorosulfonic acid in the presence or absence of an inert organic solvent.
- after bromination in the presence of sulfonic acid, without isolation, in the presence of sulfuric acid in the presence or absence of an inert organic solvent, sulfuric acid of the reaction mixture in the presence of an inert organic solvent; By adding water to adjust the concentration to 7% or more and the specific gravity of sulfuric acid to be smaller than the specific gravity of the inert organic solvent, only sulfuric acid is extracted into the aqueous layer, and water is added to the organic solvent containing the brominated product. 1-, which is characterized by adding water, extracting poorly water-soluble impurities into an organic solvent layer, and obtaining the target product from the aqueous layer.
A method for producing amino-4-bromanthraquinone-2-sulfonic acid or a salt thereof.