JPS6030305B2 - Method for producing anthraquinone intermediates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing anthraquinone-based intermediates that are particularly useful in the dye industry. After dibromination to give 1-amino-2,4-dibromoanthraquinone, this compound is extracted and separated from an inert organic solvent using sulfuric acid without isolation, and after adjusting the sulfuric acid concentration as necessary, the presence of shelf acid is determined. This is a method for producing anthraquinone-based intermediates, which is characterized by hydrolyzing the 1-amino-2-from-4-hydroxyanthraquinone.

Conventionally, a method for producing 1-amino-2-from-4-hydroxyanthraquinone is a method in which 1-amino-2,4-dibromo-anthraquinone is hydrolyzed in concentrated sulfuric acid or fuming sulfuric acid in the presence of a shelf acid (PB Report No. 86
139 page 5 and USP 2604408), 1-Ami/
Method for brominating 14-hydroxyanthraquinone (
Journal of the Society of Organic Synthetic Chemistry 17, p. 140), 3'-nitro-
A method of ring-closing 4'-bromobenzoylbenzoic acid (Japanese Unexamined Patent Publication No. 48-68626) is known.

However, the second and third methods are not industrially advantageous because the synthesis of the precursor is not easy compared to the first method.

In addition, as a method for producing 1-amino-2,4-dibromoanthraquinone, which is a raw material for the first method, a method of dibrominating 1-aminoanthraquinone-2-sulfonic acid in an aqueous solvent (J.C.S. .193 hair curtain 816 pages, USP2
169196), Process for the bromination of 1-aminoanthraquinone in nitrobenzene (Mer. 49 216i
BP 1239778), similarly promation in monochlorobenzene (USSRI 96763), and 1-
A method of dissolving aminoanthraquinone in sulfuric acid, discharging it into water, atomizing it, and converting it to dibromination in the aqueous dispersion (
PB report no. 8613, p. 6) is publicly known.

However, each bromination method requires a different hydrolysis step and reaction system, so it is necessary to prepare the dibrome compound in one day.
Therefore, steps of filtration, washing, and drying are also necessary. As a result, the manufacturing method that has been adopted as the most industrially advantageous method to date for producing 1-amino-2-from-4-hydroxyanthraquinone is to dissolve 1-aminoanthraquinone in sulfuric acid and then drain it into water. In this method, the compound is pulverized, dibrominated in an aqueous dispersion, and after the bromination is completed, the dibromine compound is isolated by oven filtration and drying, and then hydrolyzed in concentrated sulfuric acid or fuming sulfuric acid in the presence of a shelf acid. The present inventors have conducted intensive studies on a method that can industrially advantageously produce 1-amino-2-bromo-4-hydroxyanthraquinone using a consistent process. After dibromination in the presence of a deoxidizing agent, the reaction product is extracted and separated from an inert organic solvent using sulfuric acid without isolation, and if necessary the sulfuric acid concentration is adjusted to water, oleum or chlorosulfonic acid, etc. 1-Amino-2-from-4-hydroxyanthraquinone can be obtained in a high yield by adjusting it with a shelf acid, adding a shelf acid, and hydrolyzing it, without going through the complicated process of isolating the dibrominated product. I saw it and put it out.

In addition, in the method of the present invention, since the dibromination method in the aqueous dispersion involves reacting 1-aminoanthraquinone with bromine in a suspended state, the unreacted monobrominated 1-amino-2-brominated 1-amino-2-brominated 1-aminoanthraquinone is constantly 4% of the product, impurities are generated in the subsequent hydrolysis, resulting in poor yield and quality. However, since it is easily converted to dibrome compounds in the bromination process, The yield and quality of the decomposition products are excellent.

In addition, in the method of the present invention, when the reaction product is extracted and separated into sulfuric acid using sulfuric acid after dibromination, the remaining hydrogen bromide generated during bromination or the bromide generated by contact with the deoxidizing agent is sulfuric acid. Since the bromine is easily converted into bromine in the organic solvent and the bromine is back-extracted into an inert organic solvent, it is extremely advantageous in that bromine can be recycled without waste by reusing the inert organic solvent.

In other words, during dibromination in an organic solvent, stoichiometrically more than 2 moles of bromine are required, but in reality only half of the expensive bromine is used. On the other hand, in the method of the present invention, only 1 mole of bromine is consumed by using sulfuric acid, and most of the remaining 1 mole is recovered, making it an economically extremely advantageous method. In the present invention, the inert organic solvent is an organic solvent that has no phase affinity with sulfuric acid and is inert to bromination, and includes halogenated aromatic hydrocarbons such as chlorobenzeso, dichlorobenzene, trichlorobenzene, and dichloroethane. ,
Aliphatic hydrocarbons such as tetrachloroethane, trichlorethylene or tetrachloroethylene are suitable, particularly 1,2-dichlorobenzene.

Bromine is preferably used as the brominating agent, and the amount used is preferably in the range of 2.0 to 3.0 molar ratio per 1 mole of 1-aminoanthraquinone. When reusing, the amount used may be substantially in a molar ratio of 1.0 to 1.5.

Carbonates, bicarbonates, oxides, or acetates of alkali metals or alkali metals are used as deoxidizers, and specifically, sodium carbonate, magnesium oxide, sodium acetate, etc. are used. The amount used is equivalent to or slightly in excess of the hydrogen bromide generated. Dibromination usually proceeds at 20 to 100 q○, but industrially it is particularly preferable to react at 40 to 80 q○.

The reaction time varies depending on the reaction temperature, but is usually 2 hours to 1 period. Concentrated sulfuric acid or fuming sulfuric acid is used as the sulfuric acid in the extraction step subsequent to dibromination, and the amount used is 7 to 15 times the weight of 1-aminoanthraquinone, and the extraction temperature is between 30 and 10,000.

Generally, when the temperature is low, it is preferable to increase the concentration of sulfuric acid or increase the amount used to perform extraction in a state in which the dibrominated product is completely dissolved in the sulfuric acid. The operating conditions of the machine are also designed to ensure complete oxidation of hydrogen bromide or bromide to bromine in sulfuric acid and sufficient back extraction of bromine into an organic solvent. The sulfuric acid solution of the dibromide separated in this way can be hydrolyzed as is, or if the extracted sulfuric acid concentration is low, the sulfuric acid concentration can be increased to 95% or more by adding sulfuric acid, fuming sulfuric acid, or chlorosulfonic acid prior to hydrolysis. In this way, 1-amino-2-bromo-4-hydroxyanthraquinone can be obtained. On the other hand, since only bromine is dissolved in the organic solvent and does not contain any other impurities, it can be reused as a solvent for dibromination, and the amount of bromine added at this time is equal to the amount consumed as dibromination. Just add it.

The reaction temperature for hydrolysis is preferably in the range of 100 to 14,000, and when the sulfuric acid concentration is low, the hydrolysis rate is slow, so a high temperature and long reaction time is required.

Furthermore, if the concentration of fuming sulfuric acid is too high, particularly if it exceeds 5%, there is a tendency for by-products to increase. The amount of willow acid used is suitably about 1 to 3 molar ratio to the anthraquinone compound.

1-Amino-2-from-4- thus obtained
Hydroxyanthraquinone is extremely valuable as a dye intermediate, and the industrial value of the present invention is great.
Next, the present invention will be explained with reference to Examples.

In the text, parts mean parts by weight. Example 1 Add 11 $ of 1,2-dichlorobenzene, 11.2 parts of 1-aminoanthraquinone and 6.36 parts of sodium carbonate, add 19.2 parts of bromine at room temperature, and then add 50 q.
The temperature was raised to 0.0 and kept at the same temperature for 7 hours.

In order to confirm the furomation reaction, the production ratio of the products was determined by gas chromatography, and it was found that 99.4% of 1-amino/-2,4-dibromoisotraquinone, 1-amino-2-
From anthraquinone was 0.2%, and 1-amino-4-from anthraquinone was 0.4%. Then 100%
Add 86 parts of sulfuric acid at 5000 °C, heat for 2 hours at 70 o'clock, and after standing at the same temperature for 15 minutes, separate the sulfuric acid layer, then add 4 parts of acid anhydride and raise the temperature to 120 o'clock.

The mixture was kept at the same temperature for about 5 hours until unreacted 1-amino-2,4-dibromine disappeared. After the reaction was completed, the reaction mixture was cooled to room temperature and poured into 560 parts of water, and the precipitated crystals were filtered, washed, and dried to obtain 16 parts of a cake having a melting point of 228 to 23,200. This almost coincided with the literature value of melting point 231-23 of 1-amino-2-from-4-hydroxyanthraquinone, which is 0. In addition, the elemental analysis values almost agreed with the calculated values. C
% H% N% Br% Calculated value 52.862.534.4025.12 Actual value 52.922.504.4224.91 Example
2. 1-Aminoanthraquinone 11. Add bromine and 6.36 parts of sodium carbonate, and add 8.36 parts of bromine at room temperature.
．． Added 8 parts.

Thereafter, the same operations and treatments as in Example 1 were carried out to obtain 16.2 cakes of 1-amino-2-from-4-hydroxyanthraquinone having the same quality as in Example 1. Example 3 22.3 parts of 1-aminoanthraquinone and 4.42 parts of magnesium oxide were added to 216 parts of monochlorobenzene,
After adding 36.6 parts of bromine under the 5,000 flask, 60 to 70
It was kept warm at ℃ for 4 hours.

To confirm the furomation reaction, the production ratio of the product was determined by gas chromatography, and it was found that 1-amino-2,4-
Dibromoanthraquinone 99.6%, 1-amino-4-
From anthraquinone was 0.4%. Then 98
Add 112 parts of % sulfuric acid, stir at 90℃ for 2 hours, and at the same temperature add 112 parts of sulfuric acid.
After standing for 5 minutes, the sulfuric acid layer was separated, and then 112 parts of 25% oleum was added, followed by 12.3 parts of side acid.
Raise the temperature to 0.

Claims (1)

[Claims] 1 1-Aminoanthraquinone is dibrominated to 1-amino-2,4-dibromanthraquinone in the presence of an acid scavenger in an inert organic solvent, and then the compound is inactivated using sulfuric acid without isolation. An anthraquinone intermediate, which is extracted and separated from an organic solvent, adjusted as necessary to adjust the sulfuric acid concentration, and then hydrolyzed in the presence of boric acid to yield 1-amino-2-bromo-4-hydroxyanthraquinone. Manufacturing method.