JPH0143737B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improved method for producing 1-amino-4-bromoanthraquinone-2-sulfonic acid or a salt thereof. More specifically, the present invention provides 1-amino-4-bromanthraquinone-2-, which is characterized by brominating 1-aminoanthraquinone-2-sulfonic acid in the presence of sulfuric acid or fuming sulfuric acid in an inert organic solvent. This is a method for producing sulfonic acid or its salt.

1-amino-4-bromoanthraquinone-2-
Sulfonic 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- Bromoanthraquinone and 1-amino-
It is known that 2,4-dibromoanthraquinone is produced and the yield is reduced. Methods for preventing the formation of these by-products are known from known literature, and can be broadly classified as follows.

One method is to salt out or neutralize 1-aminoanthraquinone-2-sulfonic acid in water to form fine crystals of the alkali metal salt of 1-aminoanthraquinone-2-sulfonic acid, which is then brominated. Among these methods, a method in which bromination is carried out under weak acidity is a particularly improved method.
(West German Patent No. 2303746, Czechoslovakia Patent No.
(No. 169459) However, although this method can suppress the production of by-products, the crystal form of the alkali metal salt of 1-aminoanthraquinone-2-sulfonic acid is not suitable (if it is not thin needle crystals), or the formation of by-products during bromination may be If mixing is not sufficient, unreacted 1-aminoanthraquinone-2-
It has the disadvantage that a large amount of sulfonic acid remains and the yield of the target product is low.

The other method involves brominating 1-aminoanthraquinone-2-sulfonic acid in concentrated sulfuric acid. (Ciekoslovakia Patent No. 122317, JP-A-54-48749) These methods are based on 1-aminoanthraquinone-
Since bromination is carried out with 2-sulfonic acid completely dissolved in sulfuric acid, problems such as crystal formation and mixing do not occur as in the former case, but a large amount of waste sulfuric acid (usually 1-aminoanthraquinone-2 - at least 8 molar ratio relative to sulfonic acid), which has the drawback of requiring enormous costs and labor for wastewater treatment or recovery of sulfuric acid.

In order to overcome the above-mentioned drawbacks, the present inventors have conducted intensive studies focusing on the possibility of reducing the amount of sulfuric acid, and have found that when brominating 1-aminoanthraquinone-2-sulfonic acid, this reaction can be carried out using the conventional method. 1-Amino-4-
The present invention was completed by discovering that bromoanthraquinone-2-sulfonic acid can be obtained in high yield.

Examples of the inert organic solvent used in the present invention include halogenated hydrocarbons such as monochlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and 1,3,5-trichlorobenzene; Aliphatic halogenated hydrocarbons such as tetrachloroethane and tetrachloroethylene, n
-Saturated hydrocarbons such as heptane and nitrobenzene.

The amount used is 1-aminoanthraquinone-2-
It is 2-20 times the weight of sulfonic acid. Industrially, chlorobenzene or 1,2-dichlorobenzene is preferably used.

In the present invention, sulfuric acid is 65% or more concentrated sulfuric acid or 20%
% or less of fuming sulfuric acid, preferably more than 80% concentrated sulfuric acid or less than 10% fuming sulfuric acid. The amount used is less than 8 molar ratio to 1-aminoanthraquinone-2-sulfonic acid, preferably 0.5-7.5
The molar ratio is more preferably 0.9-7.0 molar ratio.

In the present invention, the brominating agent includes bromine or an alkali metal bromide such as sodium bromide or potassium bromide, or hydrogen bromide.
When bromine is used, the amount used is 0.5 to 1.3 molar ratio to 1-aminoanthraquinone-2-sulfonic acid. When an alkali metal bromide or hydrogen bromide is used, the appropriate amount thereof is 1 to 2.6 molar ratio to 1-aminoanthraquinone-2-sulfonic acid.

In the present invention, the reaction temperature is 60-140°C, preferably 80-120°C. A conventional halogenation catalyst such as iodine may be added during the reaction. Also effective are nitrogen-containing heterocyclic bases such as pyridine and quinoline. The brominating agent is preferably added gradually at the reaction temperature. This time is usually 5-24 hours.

In the present invention, since the amount of sulfuric acid or fuming sulfuric acid used is small, the reaction always proceeds with the crystals suspended in the inert organic solvent. In this respect, the method of the present invention is significantly different from the known bromination method in sulfuric acid, in which the reaction is carried out in a state dissolved in sulfuric acid. Furthermore, it was unexpected that the desired product could be obtained in high yield using a previously unimaginable amount of sulfuric acid or fuming sulfuric acid, as in the method of the present invention. This is only possible in the presence of an inert organic solvent to improve the efficiency of stirring and heat transfer.

Furthermore, it is known that 1-aminoanthraquinone-2-sulfonic acid can be obtained in good yield by reacting 1-aminoanthraquinone with a conventional sulfonating agent such as chlorosulfonic acid or sulfuric acid in an inert organic solvent. There is. By combining this method and the method of the present invention, 1-amino-4-
Bromoanthraquinone-2-sulfonic acid is 1-
It is possible to easily produce 1-aminoanthraquinone-2-sulfonic acid from aminoanthraquinone in one pot with good yield without isolating it during the process. Therefore, the industrial value of the present invention is extremely large.

Post-treatment and purification steps after the completion of the reaction can be carried out by methods known per se, for example, as follows.

After the reaction is complete, excess bromine is removed and the reaction mixture is diluted with water to dissolve 1-amino-4-bromoanthraquinone-2-sulfonic acid in the aqueous layer. The inert organic solvent layer dissolves a small amount of by-product 1-amino-2,4-dibromoanthraquinone, etc., and is therefore separated. By adding alkali to the aqueous layer to adjust the concentration of Glauber's sulfate to an appropriate level and separating the precipitated crystals, a highly pure target product containing almost no by-products can be obtained.

Next, the present invention will be explained in more detail with reference to Examples. In the text, parts represent parts by weight, and % represents weight %.

Example 1 150 parts of 1,2-dichlorobenzene and 32.2 parts of 1-aminoanthraquinone-2-sulfonic acid with a purity of 94%
50.0 parts of 98% sulfuric acid was added dropwise at 70°C over 1 hour while thoroughly stirring. Next, 0.5 part of iodine was added at the same temperature, and the temperature was raised to 98°C to remove bromine.
14.4 parts were added dropwise over 10 hours. According to chromatography, 1-aminoanthraquinone-2-sulfonic acid had almost disappeared. After removing excess bromine under reduced pressure, 400 parts of water was added to the reaction mixture.
Stir at 90-95℃ for 10 minutes, let stand for 30 minutes,
The dichlorobenzene layer was separated. 80 parts of a 48% sodium hydroxide aqueous solution was added dropwise to the aqueous layer at 85°C, and the mixture was heated to 30°C.
The mixture was cooled to , separated and dried to obtain 40.1 parts of orange crystals. The results of compositional analysis were as follows.

1-Amino-4-bromoanthraquinone-2-sulfonic acid 89.4% 1-aminoanthraquinone-2-sulfonic acid
0.5% 1-amino-2,4-dibromoanthraquinone
0.05% 1-Amino-4-Bromanthraquinone 0.05% 1-Amino-4-Bromanthraquinone-2-
The yield of sulfonic acid was 94%.

Example 2 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 is refluxed, and the water produced by the sulfonation reaction is 1,2-dichlorobenzene.
It was condensed in the middle of the dichlorobenzene reflux system, separated and extracted. After the reaction was completed, the mixture was cooled to 95°C, 10 parts of 4% fuming sulfuric acid was added, and then 14.4 parts of bromine was added dropwise over 20 hours at a temperature in the range of 95 to 98°C. According to chromatography, the bromination reaction was complete. After removing excess bromine under reduced pressure, 500 g of water was added to the reaction mixture.
The desired product was dissolved at 90° to 95°C, heated to remove a trace amount of insoluble matter, and then allowed to stand for liquid separation to separate the 1,2-dichlorobenzene layer. 16.5 parts of a 48% sodium hydroxide aqueous solution was added dropwise to the aqueous layer at 85°C, then cooled to 30°C and the precipitated crystals were separated.
After drying, 40.0 parts of orange crystals were obtained. The results of compositional analysis were as follows.

1-Amino-4-bromanthraquinone-2-sulfonic acid 88.9% 1-aminoanthraquinone-2-sulfonic acid
0.4% 1-amino-2,4-dibromoanthraquinone
0.02% 1-Amino-4-Bromanthraquinone 0.03% 1-Amino-4-Bromanthraquinone-2-
The yield of sulfonic acid was 89.3% calculated from 1-aminoanthraquinone.

Example 3 23.7 parts of 1-aminoanthraquinone with a purity of 98% was added to 300 parts of 1,2-dichlorobenzene, and then 12.7 parts of chlorosulfonic acid was added dropwise with stirring at 20°C. Next, the temperature was raised to 120°C and kept at the same temperature for 5 hours. After the reaction is complete, inhale the HCl gas, and then
The mixture was cooled to 21.3 parts of 90% sulfuric acid, 7.9 parts of pyridine, and 0.5 parts of iodine, and 12.4 parts of bromine was added dropwise at 95-100°C over 12 hours. After the reaction, Example 2
The same treatment as above was carried out to obtain 39.7 parts of orange crystals.

The compositional analysis was as follows.

1-amino-4-bromoanthraquinone-2-sulfonic acid 88.1% 1-aminoanthraquinone-2-sulfonic acid
0.5% 1-amino-2,4-dibromoanthraquinone
0.04% 1-Amino-4-Bromanthraquinone 0.06% 1-Amino-4-Bromanthraquinone-2-
The yield of sulfonic acid was 88% calculated from 1-aminoanthraquinone.

Claims (1)

[Claims] 1 1-Aminoanthraquinone-2-sulfonic acid is brominated in the presence of sulfuric acid or oleum in a molar ratio of 8 or less to 1-aminoanthraquinone-2-sulfonic acid in an inert organic solvent. 1-amino-4-bromoanthraquinone-2, characterized by
-Production method of sulfonic acid or its salt. 2. After reacting 1-aminoanthraquinone with sulfuric acid, fuming sulfuric acid, or chlorosulfonic acid in an inert organic solvent to form 1-aminoanthraquinone-2-sulfonic acid, without isolating this product, 1 -1-Amino-4- characterized by being brominated in the presence of sulfuric acid or fuming sulfuric acid at a molar ratio of 8 or less to amino-anthraquinone-2-sulfonic acid.
A method for producing bromoanthraquinone-2-sulfonic acid or a salt thereof.