JPS6058229B2 - Process for producing 1-amino-4-bromanthraquinone-2-sulfonic acid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved process for the preparation of 1-amino-4-bromoanthraquinone-2-sulfonic acid.

More specifically, the present invention involves sulfonating 1-aminoanthraquinone with chlorosulfonic acid or sulfuric acid in a water-immiscible inert organic solvent, and then adding water to the reaction mixture to form 1-aminoanthraquinone-2. - 1- characterized in that sulfonic acid is extracted and brominated using the obtained aqueous solution of 1-aminoanthraquinone-2-sulfonic acid.
This is a method for producing amino-4-bromoanthraquinone-2-sulfonic acid.

1-Amino-4-bromoanthraquinone-2-sulfonic acid (hereinafter referred to as bromamic acid) can be obtained by sulfonating and then brominating anthonoanthraquinone.

A method for sulfonating 1-aminoanthraquinone is a method of sulfonating 1-aminoanthraquinone in sulfuric acid containing 503 (German Patent Nos. 263395 and 4).
No. 84997) is known, and the resulting 1-aminoanthraquinone-2-sulfonic acid is isolated and brominated in the next step, or directly brominated in sulfuric acid (Japanese Patent Application Laid-open No. 48747/1983). ) to obtain bromamic acid.

This sulfonation method uses a large amount of sulfuric acid or fuming sulfuric acid (several times the amount of 1-aminoanthraquinone is used). Therefore, since a large amount of waste sulfuric acid is generated, measures to deal with it are required, which cannot be said to be advantageous.

On the other hand, a method using chlorosulfonic acid in an inert organic solvent immiscible with water (U.S. Patent Nos. 2,135,346 and 2,581,016) and a method using sulfuric acid in an inert organic solvent (PB Report 73,888C) P , 126
0) is known, and in this case, the amount of chlorosulfonic acid or sulfuric acid used is about 1.0 to 1.3 moles relative to 1-aminoanthraquinone, which is almost the theoretical amount. Therefore, it is advantageous in that there are fewer problems with waste acid. In this case, the method for removing 1-aminoanthraquinone-2-sulfonic acid is to separate the organic solvent by steam distilling the entire reaction mixture, obtain an aqueous solution of 1-aminoanthraquinone-2-sulfonic acid, and then add sodium chloride. Either by salting out and isolating it as a sodium salt, or in some cases using it as it is for the next step of bromination, or by neutralizing the two reaction mixture with soda ash etc. and then steam distillation or vacuum distillation. A method of removing the organic solvent to take out the sodium salt of 1-aminoanthraquinone-2-sulfonic acid is known. Additionally, a method is known in which 1-aminoanthraquinone-2-sulfonic acid is separated from the inert organic solvent as a sulfuric acid solution by sulfonating with chlorosulfonic acid in an inert organic solvent and then extracting with sulfuric acid ( Japanese Unexamined Patent Publication 1976-1976
No. 848). These 1-aminoanthraquinone-2-
Among the methods for separating sulfonic acid, method 1 of separating an inert organic solvent by steam distillation requires a large amount of steam and consumes a large amount of thermal energy. The aqueous solution has a very low concentration and needs to be concentrated in order to carry out the next reaction.

Furthermore, there is a drawback that unreacted 1-aminoanthraquinone and sulfonated by-products remain, making purification operations cumbersome. In method 2, since 1-aminoanthraquinone-2-sulfonic acid exists as a sodium salt that is poorly soluble in water during the neutralization step, purification of residual unreacted and impurities is required more than in method 1. It has the disadvantage of being difficult.

Method 3 has the drawback that a large amount of sulfuric acid is required for extraction, which inevitably results in a large amount of waste sulfuric acid, which requires measures to dispose of it. Moreover, since all unreacted raw materials and impurities are extracted from the organic solvent layer into the sulfuric acid layer, there is a drawback that a purification operation is naturally required for isolation or in the next bromination step. The present inventors sulfonated 1-aminoanthraquinone as a starting material and then brominated it to obtain promamic acid. As a result of intensive study on a manufacturing method that does not have the above-mentioned drawbacks, the present invention was achieved. did.

In the present invention, an aqueous solution of 1-aminoanthraquinone-2-sulfonic acid with a higher concentration than expected can be obtained by sulfonation with chlorosulfonic acid or sulfuric acid in an inert organic solvent, followed by extraction with water. It is based on what we have discovered.

1-Aminoanthraquinone-2-sulfonic acid sodium salt (or other alkali metal salt, ammonium salt) has a solubility in water of 1-2% by weight at 20°C, whereas 1-aminoanthraquinone-2- It was surprising that sulfonic acid has a high water solubility of about 25% by weight at 0 to 90°C almost regardless of temperature.

Further advantageously, anthraquinone contained in the raw material 1-aminoanthraquinone and unsulfonated 1-aminoanthraquinone remain dissolved in the organic solvent and do not migrate to the 1-aminoanthraquinone-2-sulfonic acid aqueous solution. 1-Amino-4, which is highly pure even without purification procedures,
Anthraquinone-2-sulfonic acid is obtained.

Furthermore, unlike known methods, the method of the present invention does not use a large amount of sulfuric acid, so almost no waste acid is generated, and furthermore, since steam distillation is not required, there is an advantage that less thermal energy is consumed.

In addition, the concentration of the 1-aminoanthraquinone-2-sulfonic acid aqueous solution can be freely set in accordance with the next bromination step. This is very suitable for carrying out the bromination reaction continuously. Promamic acid obtained by the method of the present invention is
Not only when the purity of 1-aminoanthraquinone as a raw material is high, but even when the purity is low, the content of impurities is relatively small and it can be obtained in high yield.

In the present invention, the water-immiscible inert organic solvent is
It is an organic solvent that is incompatible with water and inert to sulfonation, such as halogenated aromatic hydrocarbons such as monochlorobenzene, dichloroflbenzene, and trichlorobenzene, halogenated aliphatic hydrocarbons such as Tetrakchoretan, Examples include nitrobenzene, and 1,2-dichlorobenzene is particularly preferred.

The sulfonation reaction is carried out using these organic solvents as described in US Pat. No. 2,135,346 or US Pat. ．． P. It can be carried out according to the method described in No. 1260.

After sulfonation, water is added to the sulfonation reaction solution, stirred, and then allowed to stand still.

The organic layer and the aqueous phase are separated to obtain a 1-aminoanthraquinone-2-sulfonic acid aqueous solution.

Here, the purity of the raw material 1-aminoanthraquinone is low (
Contains impurities such as anthraquinone, 2-aminoanthraquinone, 1,4-, 1,5-, or 1,8-diaminoanthraquinone), therefore, higher-order sulfonated products are produced as by-products by sulfonation, and the fraction during extraction is When the liquid interface is unclear, the liquid separation operation becomes easier by performing activated carbon treatment. The amount of water added to the sulfonation reaction solution is determined based on the amount of 1-aminoanthraquinone-2-sulfonic acid produced.
, but it is sufficient that the amount is at least 3 times the weight; anything less than this is not preferable as it may cause problems in the extraction operation. Further, although the use of water in an amount of 3 times or more by weight does not have any particular adverse effect on the extraction operation, it is not desirable to use more than necessary. The amount of water to be used is appropriately determined in consideration of the concentration required for the next bromination step. The extraction operation can be performed once or in several parts. To avoid contamination with organic solvent, separate the water layer by leaving a small amount of water, then add fresh water and perform the extraction operation.The resulting aqueous layer is used in the first batch of the next batch. It is a rational and preferable method to recycle the water for extraction. Using the aqueous solution of 1-aminoanthraquinone-2-sulfonic acid thus obtained, a bromination reaction is carried out in an aqueous medium.

Any known method can be applied to the bromination reaction in an aqueous medium. One of them is the method described in JP-A-55-19231, in which an aqueous solution of 1-aminoanthraquinone-2-sulfonic acid is neutralized with an alkali to form an alkali salt of 1-aminoanthraquinone-2-sulfonic acid. After that, bromination is carried out by adding appropriate additives.

This method is carried out using a concentration of 1-aminoanthraquinone-2-sulfonic acid that is generally 10 to 2% by volume;
The present invention has a preferred method. Another bromination method is to carry out bromination in the presence of an electrolyte after neutralization.

This method is described, for example, in U.S. Pat.
No. 4407(1), No. 2503254, FIATl
3l3■, page 214, and the concentration of 1-aminoanthraquinone-2-sulfonic acid is usually 2.5-3.
5% by weight. These two methods are both reactions in which sodium 1-aminoanthraquinone-2-sulfonate is suspended in water, and require fine crystals. When performing bromination using the neutralization method, by simply neutralizing an aqueous solution of 1-aminoanthraquinone-2-sulfonic acid using caustic soda, finely divided sodium 1-aminoanthraquinone-2-sulfonic acid suitable for the reaction can be obtained. It is highly advantageous that salts can be easily obtained. In addition, in the present invention, 1-aminoanthraquinone-2-sulfonic acid is first extracted from the aqueous solution of 1-aminoanthraquinone-2-sulfonic acid obtained by extraction.
- It is also possible to carry out the bromination method described above after isolation of the sulfonic acid as a salt.

The present invention will be explained below with reference to Examples.

In the examples, parts and % are by weight unless otherwise specified.
means.

Example 1 800 parts of 1,2-dichlorobenzene, purity 98.0%
102 parts of 1-aminoanthraquinone was suspended, then 62.4 parts of chlorosulfonic acid was added dropwise, and the mixture was heated to 110°C.
The mixture is stirred at 110 to 115° C. until the amount of unreacted 1-aminoanthraquinone becomes 1% or less.

After cooling to below 100°C, 516 parts of water was added, stirred, and then transferred to a separation tank and left to stand. Among the upper aqueous layer containing 1-aminoanthraquinone-2-sulfonic acid, the area near the interface was unclear. The transparent portion was separated to obtain a concentrated aqueous solution of 1-aminoanthraquinone-2-sulfonic acid having 580 blades.

As a result of the analysis, the concentration of 1-aminoanthraquinone-2-sulfonic acid was 20%, and the content was 116. Part I was prepared. Water 46 is newly added to the lower 1●2-dichlorobenzene layer.
4. (2) was added and extracted repeatedly to obtain 502.5 parts of a dilute solution of 1-aminoanthraquinone-2-sulfonic acid. The concentration is 2.4%, and the content is 12 rainbow parts.The dilute solution of hot crab can be recycled as the next first extraction water). The total theoretical yield of 1-aminoanthraquinone-2-sulfonic acid separated and extracted as an aqueous solution from 1-aminoanthraquinone was 94.3%.

1-Aminoanthraquinone-2-sulfonic acid 116.1
To 502.5 parts of a 20% concentrated aqueous solution containing
-Sodium aminoanthraquinone-2-sulfonate is precipitated.

Then 28.3 parts of sodium acetate was added and the mixture was heated to -1 to 1°C.
Bromine in the range of 42. The solution was added dropwise over a period of 2 hours, during which time the pH of the system was adjusted to 5.5-6.
It was kept at 5. Then, sodium hypochlorite aqueous solution (N
aOCl content 12.0%) 100.7 parts -1 to +1
It took 4 hours to add dropwise at
H was maintained between 5.5 and 6.5. Next, after eliminating excess bromine with sodium sulfite, the product was filtered through p-filtration to obtain the desired product.

When the yield based on 1-aminoanthraquinone-2-sulfonic acid was determined, the following results were obtained.

Sodium promamate 93.8%1
-Amino-2-bromanthraquinone 1.2% 1-amino-2,4-dibromanthraquinone
2.9% unreacted raw material
2.1% Example 2 1002 parts of 1-aminoanthraquinone with a purity of 99.8% was suspended in 1000 parts of 1-2-dichlorobenzene, and then 49% of 98% sulfuric acid was added.
Drop 3 parts.

The temperature is raised to the boiling point, and the mixture is stirred while being kept warm under reflux until the amount of unreacted 1-aminoanthraquinone becomes 2% or less. After cooling to below 100°C, 746.5 parts of water and 6.6 parts of activated carbon were added,
After stirring, it is filtered.

Next, the liquor liquid is transferred to a separating tank and allowed to stand, and the upper aqueous layer is separated. 1-aminoanthraquinone-2-sulfonic acid
834.3 parts (concentration 15%) of a concentrated solution containing 25.1 parts were obtained.

Furthermore, 300 parts of water was newly added to the lower 1,2-dichlorobenzene layer and extracted to obtain 1-aminoanthraquinone-2-
275.1 parts of a dilute aqueous solution (concentration 1.9%) containing 51 parts of sulfonic acid was obtained. The total yield of 1-aminoanthraquinone-2-sulfonic acid separated and extracted as an aqueous solution from 1-aminoanthraquinone was 95.9%.

1-aminoanthraquinone-2-sulfonic acid 125.1
834.3 parts of a 15% concentrated aqueous solution containing 37.0 parts of acetic acid
of 45% aqueous sodium hydroxide at below 10°C.
A portion of Liquid 91 was added under stirring to precipitate sodium 1-aminoanthraquinone-2-sulfonate.

Then, 7.1 parts of bromine was added dropwise over 4 hours at -1 to +1°C.
During this time, the pH in the system was maintained at 5.5 to 6.5 using a dilute aqueous sodium hydroxide solution. Next, 108.5 parts of a sodium hypochlorite aqueous solution (NaOCl content 12.0%) was added dropwise at -1 to +1°C over 4 hours, and during this time the pH in the system was lowered to 5.5 using a dilute sulfuric acid aqueous solution. Maintain at ~6.5.

Excess bromine was then removed with sodium sulfite, and the mixture was allowed to stay overnight to obtain sodium promamate. When the yield based on 1-aminoanthraquinone-2-sulfonic acid was determined, the following results were obtained.

Sodium promamate 94.7%1
-Amino-2-bromanthraquinone 0.3% 1-amino-2●4-dibromanthraquinone
3.2% unreacted raw material
1.8% Example 3 111 parts of 1-aminoanthraquinone with a purity of 90% (the remaining 10% is anthraquinone) was suspended in 1,000 parts of 1.2-dichloride lebenzene, and then 63 parts of chlorosulfonic acid was added dropwise. After that, the temperature is raised to 110°C.

Stir while keeping warm at 110-115°C until unreacted 1-aminoanthraquinone becomes 1.0% or less.

After cooling to below 100°C, 1744 parts of water and 10 parts of activated carbon
Add katabe, stir, and filter.

Transfer the liquid to a separation tank and leave it to stand to separate the aqueous layer. A concentrated aqueous solution (concentration 7.5%) containing 129 parts of 1-aminoanthraquinone-2-sulfonic acid was obtained.

Impurities other than the main component in this aqueous solution, anthraquinone,
The content of 1-aminoanthraquinone and other components was 0.1% or less. Further, 137 parts of water is added to 17 parts of the 1-aminoanthraquinone-2-sulfonic acid aqueous solution, and 14 parts of sodium chloride is added at 0 to 1°C to precipitate sodium 1-aminoanthraquinone-2-sulfonic acid.

An aqueous solution containing a bromine mark dissolved in a 17.5% hydrochloric acid aqueous solution was added dropwise at -1 to +1°C over 4 hours, and then 100 parts of a sodium hypochlorite aqueous solution (NaOCI content 12.0%) was added at -1 to +1°C. The dropwise addition took 4 hours at ℃. After removing excess bromine with sodium sulfite, the mixture was left overnight to obtain the desired product. When the yield based on 1-aminoanthraquinone-2-sulfonic acid was determined, the following results were obtained.

Claims (1)

[Claims] 1. After sulfonating 1-aminoanthraquinone with chlorosulfonic acid or sulfuric acid in a water-immiscible inert organic solvent, water is added to the reaction mixture to extract 1-aminoanthraquinone-2-sulfonic acid, A method for producing 1-amino-4-bromoanthraquinone-2-sulfonic acid, which comprises brominating using the obtained aqueous 1-aminoanthraquinone-2-sulfonic acid solution.