JPS6045870B2 - Method for producing anthraquinone intermediates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing anthraquinone intermediates which are particularly useful in the dye industry.

More specifically, 1-amino-2,4-dibromoanthraquinone is hydrolyzed in concentrated sulfuric acid or fuming sulfuric acid in the presence of boric acid and an aliphatic dicarboxylic acid or an aromatic mono- or dicarboxylic acid to form 1-amino-2-bromoanthraquinone. This is a method for producing an anthraquinone intermediate, characterized in that it is 4-hydroxyanthraquinone.

Conventionally, as a method for producing 1-amino-2-bromo-4-hydroxyanthraquinone, 1-amino-2,4-
A method of hydrolyzing dibromoanthraquinone in concentrated sulfuric acid or fuming sulfuric acid in the presence of boric acid (PB Report No.
8613-5, USP2604480, etc.), 21-
Method for brominating amino-2-bromo-4-hydroxyanthraquinone (Journal of the Society of Organic Synthesis 17, 14
0), a method for ring-closing 33'-nitro 4'-brombenzoylbenzoic acid (Japanese Patent Application Laid-Open No. 48-68626), and the like are known.

However, these methods have various problems when they are actually intended to be industrialized, and cannot be said to be advantageous methods. As an improved version of these methods, 4 Japanese Unexamined Patent Publication No. 53-120
Publication No. 7 states that 1-aminoanthraquinone is 50-8
After dibromination to give 1-amino-2,4-dibromoanthraquinone in 5% sulfuric acid, the compound was not isolated and the sulfuric acid concentration was adjusted between 96% and 5% oleum in the presence of boric acid. Hydrolyzed to 1-amino-2-bromo4
-A method for obtaining hydroxyanthraquinone is also described. However, 1-amino-2- obtained by this method
Bromo-4-hydroxyanthraquinone is not of sufficient quality and cannot be used as it is in the production of disperse dyes, and it also generates a large amount of waste acid. Also, 4 Japanese Unexamined Patent Publication No. 53
-133231 publication describes concentrated sulfuric acid, especially 85-98%
A method is described in which dibromination is carried out in sulfuric acid, followed by hydrolysis by increasing the sulfuric acid concentration if necessary.

This method can perform two steps consistently, has high productivity in that it uses highly concentrated sulfuric acid, generates little waste acid, and has excellent quality of 1-amino-2-bromo-4-
It is noteworthy that hydroxyanthraquinone can be obtained. The present inventors conducted intensive studies to obtain 1-amino-2-bromo-4-hydroxyanthraquinone of even higher quality than these conventional methods, and found that aliphatic dicarboxylic acids or aromatic Due to the presence of mono- or dicarboxylic acids, 1-amino-2-bromo4 is produced in excellent quality without by-products.
It has been found that -hydroxyanthraquinone can be obtained in high yield.

That is, according to the method of the present invention, the by-product of trace amounts of blue impurities and tar components that are produced during hydrolysis in conventional methods is suppressed, so the quality of the obtained 1-amino-2-bromo-4-hydroxyanthraquinone is significantly improved. Furthermore, the disperse dye obtained using this as a raw material gives a vivid dyed product. In the present invention, examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, and mixtures thereof.

Aromatic mono- or dicarboxylic acids include, for example, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid and mixtures thereof. The amount of these carboxylic acids added is usually 0.05-1.5 molar ratio, preferably 0.1-
A molar ratio of 1.4 is used. In the present invention, the reaction medium used is concentrated sulfuric acid, preferably 95% (by weight) or more sulfuric acid or fuming sulfuric acid, preferably 10% (by weight) or less fuming sulfuric acid.

The reaction temperature is preferably in the range of 100-140°C. The appropriate amount of boric acid to be used is about 1 to 3 molar ratio to the anthraquinone compound. Bromine, which may be generated, can be removed using inert gas or suction. It is preferable to collect and reuse the waste. 1-amino-2 used as raw material
, 4-dibromoanthraquinone can be prepared using known methods (e.g. PB Report No. 86l39, page 6, JP-A-1983-1999).
13323, etc.) can be used.

1-amino-2-bromo-4- thus obtained
Hydroxyanthraquinone is extremely valuable as a dye intermediate, and especially when used as a raw material for red disperse dyes, it can produce products with significantly improved clarity compared to those obtained by conventional methods.

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

In the text, parts and % mean parts by weight and % by weight. Example 1 4% oleum 11% boric acid in the 2 mark area. Prostitute and succinic acid 2
．． In addition to 6 copies, PB report no. 1-amino-2,4-dibromoanthraquinone obtained by the method of page 86l3, page 6 34. ? (purity equivalent value) was added, the temperature was raised under stirring, and the temperature was kept at 100°C for 1 hour, and then the temperature was raised to 120°C. Keep warm for about 5 hours until it disappears.

Gases such as bromine, hydrogen bromide and sulfur dioxide generated during this time are thoroughly removed from the system using nitrogen. After the reaction is completed, 9
After cooling to 0°C and adding 135 parts of water dropwise over 2 hours,
Filter at °C.

Wash with 1 (1) part of 60% sulfuric acid, wash with water, dry, and prepare 1-
Amino-2-bromo-4-hydroxyanthraquinone 2
8.4 parts (purity 97.6%, yield 97.2%) were obtained.

A disperse dye (C.I. Despers Thread 60) obtained using this as a raw material had excellent clarity. For comparison, a reaction was carried out in the same manner except in the absence of succinic acid, but the purity and yield were lower than that of the product of Example 1, and the disperse dye obtained using this as a raw material was particularly clear. It was considerably inferior in terms of quality. Example 2 In Example 1, JP-A No. 5
1-amino-2,4-dibromoanthraquinone obtained by the method described in Publication No. 3-133231 was prepared using PB Report No. The reaction was carried out in the same manner except that 1-amino-2,4-dibromoanthraquinone obtained by the method described on page 6 of 86l39 was used in place of the same.

28.5 parts of 1-amino-2-bromo-4-hydroxyanthraquinone (purity 98.0%, yield 97.9%) was obtained.

Example 3 In Example 1, 5.5 parts of benzoic acid or 2.3 parts of malonic acid was used instead of 2.6 parts of succinic acid, and the reaction was carried out in the same manner.

1-Amino-2-bromo-4-hydroxyanthraquinone was obtained with the following results.

O benzoic acid used, purity 96.0%, yield 96.5%

Claims (1)

[Claims] 1 Hydrolyzing 1-amino-2,4-dibromoanthraquinone in concentrated sulfuric acid or fuming sulfuric acid in the presence of boric acid and an aliphatic dicarboxylic acid or an aromatic mono- or dicarboxylic acid to produce 1-amino-2-bromo-4 - A method for producing an anthraquinone intermediate, characterized in that it is hydroxyanthraquinone.