JPS58131965A - Preparation of 1-amino-4-bromoanthraquinone-2-sulfonic acid - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as an intermediate of dye, in high yield, by using 1-aminoanthraquinone having a specific molar absorption coefficient as a starting material, sulfonating the compound with sulfuric acid or chlorosulfonic acid, and brominating in water or in sulfuric acid. CONSTITUTION:1-Aminoanthraquinone having a molar absorption coefficient of <=1.0l/cm.mol at 650nm wavelength is used as a starting compound. The compound is made to react with sulfuric acid or chlorosulfonic acid, and the resultant 1-amino-anthraquinone-2-sulfonic acid is hydrogenated in water or in sulfuric acid to obtain the objective compound. The starting compound can be prepared by nitrating anthraquinone in mixed acid, reducing with sodium hydrosulfide, and distilling the resultant reaction product in vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing anthraquinone intermediates.

More specifically, the present invention relates to l -amino- which is an intermediate useful in the dye industry.
The present invention relates to an improved method for producing 4-bromoanthraquinone-2-sulfonic acid.

1-Amino-4-bromanthraquinone-2-sulfonic acid (hereinafter referred to as promamine) is produced by sulfonating l-aminoanthraquinone to form l-aminoanthraquinone-2-sulfonic acid, which is then brominated.

The sulfonation method includes a method of reacting with chlorosulfonic acid in an inert organic solvent (US Pat. No. 218,584).
No. 6, No. 2681016], or inert organic a
Method of reacting with sulfuric acid in m (FB report 78888
0. P1260), or a method of sulfonation in an acid containing 803 (German AI Patent No. 268895, German AI Patent No. 4)
No. 84997) and the like are publicly known. A method for pro-hatching is a method in which l-aminotentraquinone-2-sulfonic acid is salted out or neutralized in water to form fine crystals of alkali metal salt and then pro-hatched (West German Patent No. 2808).
No. 746, Czechoslovakia Patent No. 169459, Japanese Patent No. 56-19281), a method of bromination in concentrated sulfuric acid (Czechoslovakia Patent No. 122817), and the like are known. In addition, a method of consistently carrying out sulfonation and profiltration (411 Publication No. 55-80610, Japanese Patent Application Laid-open No. 54-4
8747 etc.) are also known. In these methods, when commercially available ordinary 1-7 minoanthraquinone is used as a raw material, the yield of bromamic acid obtained is about 85% at most, which is by no means sufficient.

The present inventors have conducted intensive studies on methods for further improving the yield, especially regarding the quality of the raw material 1-aminoanthraquinone, and have found that even if the purity is not necessarily high, the ML value is 1.
．． The present invention has been completed by discovering that the desired product can be obtained in good yield simply by using l-aminoanthraquinone having a concentration of 0 or less and otherwise using a method known per se.

That is, in the present invention, 1-aminoanthraquinone is reacted with sulfuric acid or chlorosulfonic acid to form 1-aminoanthraquinone-2-sulfonic acid, and this is brominated in water or sulfuric acid to form 1-amino-4-bromanthraquinone-2-sulfonic acid.
In producing 2-sulfonic acid, 1-aminoanthraquinone with a molar extinction coefficient (hereinafter referred to as ML value) at a wavelength of 650 nm (hereinafter referred to as ML value) of 1.01/6114・mol (hereinafter, units are omitted) as a starting material is used. l-Amino-4-bromanthraquinone-2- characterized by
This is a method for producing sulfonic acid.

The ML value in the present invention refers to a value measured by the following operation.

(i) Accurately weigh 0.5 t of sample into a 100-volume volumetric flask.

(21N, N-dimethylformamide (special grade reagent) 7
Add 0- and heat to 60°C to dissolve.

(3) After cooling, add N,N-dimethylformamide to make 100 IIt.

(4) Place this solution in a 108 quartz cell and measure the absorbance at a wavelength of 650 nm using a spectrophotometer needle with N,N-dimethylformamide as a control.

(5) Calculate the ML value using the following formula.

xP Here, 8: Sample amount (b) P: Purity (- M: 1-aminoanthraquinone content molecular weight 228.2 E: 650 nm) Absorbance.

An example of the ML value of commercially available 1-aminoanthraquinone is shown in the table below.

Note] Sample ml/1 Kyo Kasei Reagent Grade 2 Wako Pure Chemical Reagent 8 Bayer 47 Funa 6 Sandoz It can also be obtained by purifying 1-aminoanthraquinone using an organic solvent or sulfuric acid, or by carrying out sublimation stages, but these sophisticated methods are not economical, at least on an industrial scale. Industrially, it is preferably obtained by nitrating anthraquinone in a mixed acid, reducing it with sodium sulfide, and vacuum distilling the resulting product. Samples 46 to 8 in the above table were obtained in this manner on an industrial scale.

In the present invention, the sulfonation and bromination steps may be carried out by methods known per se.

Next, the present invention will be explained with reference to Examples. The middle part of the sentence means parts by weight, and % means percent by weight.

Example 1 1,2-dichlorobenzene 700iRS with purity 97.9
Excellent, 1-aminoanthraquinone with ML value 0.5 102.
1 part was suspended and then 1.2 parts of sodium bisulfate was added. After 47 parts of 98-superior sulfuric acid was added dropwise at 100-110°C with stirring, the temperature was raised to 180°C and stirred at 180-182°C for about 8 hours until the amount of unreacted 1-aminoanthraquinone became 14 or less. During this time, produced water was removed to the outside of the thread by azeotropy. Then, after cooling the reaction mixture to 100°C, 70°C of water was added.
6.6 parts of the mixture was discharged, 8 parts of activated carbon and 10 parts of Celite were added thereto, and the mixture was stirred at 90°C. Next, the washed cake was washed with 40 parts of warm water, and the washing liquid was transferred to a separator tank and allowed to stand, and the upper aqueous layer was separated. 886.4 parts of a concentrated solution containing 127.31 parts of l-aminoanthraquinone-2-sulfonic acid was obtained. Further, 800 parts of water was newly added to the lower 1,2-dicp Lupenyan layer and extracted to obtain 275.1 parts of a dilute aqueous solution containing 5.2 parts of l-aminoanthraquinone-2-sulfonic acid. The total yield of 1-aminoanthraquinone-2-sulfonic acid separated and extracted as an aqueous solution from 1-7 aminoanthraquinone was 97.5%.

l-Aminoanthraquinone-2-sulfonic acid 127.8
87.7 parts of acetic acid was added to 886.4 parts of a concentrated aqueous solution containing 98.4 parts of a 45% sodium hydroxide aqueous solution at 10°C or below.
5 parts of l-aminoanthraquinone-2- were added under stirring.
Sodium sulfonate was precipitated. Then, 7.22 parts of bromine was added dropwise over 4 hours at 0 to 2°C, during which time the pH in the system was maintained at 6.5 to 6.5 using a dilute aqueous sodium hydroxide solution. Then, an aqueous solution of sodium hypochlorite (NaO
10 Content 12. 110.4 parts of hemorrhoids) were added dropwise over 4 hours at 0 to 2°C, and during this time the pH in the system was maintained at 6.5 to 6.5 using an aqueous solution. Excess bromine was then removed with sodium bisulfite, and the resulting cake was dissolved again in 2500 parts of 85°C warm water to dissolve poorly water-soluble 1-amino-2-bromanthraquinone and l.
-Amino-2,4-dibromoanthraquinone was filtered off. The solution was salted out with 88 parts of sodium sulfate, cooled, filtered, and then dried. 169.4 parts of sodium bromate with a purity of 94.9% was obtained. Yield based on 1-aminoanthraquinone-2-sulfonic acid: 94.7kg.

Comparative Example 1 The same operation as in Example 1 was performed with purity of 98.2 & ML value of 5.9.
The experiment was carried out using 101.8 parts of 1-7 minoandraquinone. After completion of the sulfonation reaction, water extraction was carried out twice and the total yield of 1-aminoanthraquinone-2-sulfoshi separated as an aqueous solution from 1-aminoanthraquinone was 95.0%.

Bromination was carried out in the same manner as in Example 1 using 8 [885 parts] of concentrated water containing 125.1 parts of 1-7 minoanthraquinone-2-sulfonic acid for the first time, and the purity was 98.0.
% proamic acid was obtained. Yield 8 g, 5% based on 1-aminoanthraquinone-2-sulfone.

Example 2 Purity 94.2 in 800 parts of 1,2-dichlorobenzene
m, 1-aminoant-74/n106 with ML value 0.6
．． Two parts were suspended and then 62.4 m of chlorosulfonic acid was quickly added dropwise. 14 at 110℃~115℃ by increasing temperature
It heated up for a while and became healthy. After cooling to below 70° C., 800 parts of loo*# acid was added, and the mixture was separated using a stirred apparatus. 60 parts of bromine was added dropwise over 4 hours to the sulfur solution from which the 1-aminoanthraquinone-2-sulfonic acid in the lower layer had been extracted at a temperature range of 96 to 98°C, and unreacted 1-aminoanthraquinone-2-sulfonic acid was further removed. The mixture was kept at 98° C. and stirred until it became 1% or less. After the reaction was completed, it was cooled to 50°C, discharged into warm water, and diluted to a sulfuric acid concentration of 109%. Then, it was filtered, washed with warm water, and washed with 1.
800 parts of 2-dichlorobenzene was charged and stirred, followed by liquid separation using an apparatus. 4596 sodium hydroxide was added to the aqueous layer for salting out, and the mixture was filtered and dried at room temperature to obtain 172.9 parts of sodium bromate with a purity of 94.5%. Yield 90.2% from 1-aminoanthraquinone.

Comparative Example 2 The same operation as in Example 2 was carried out with a purity of 96.0% and an ML value of 18.
It was carried out using 1-7 minoanthraquinone of 8. The yield of sodium bromamate was 88.0%.

Claims (1)

[Claims] 1-7 Minoanthraquinone is reacted with sulfuric acid or chlorosulfonic acid to give l-aminoanthraquinone-2-sulfonic acid, which is then brominated in water or sulfuric acid to form l-aminoanthraquinone-2-sulfonic acid.
- In producing amino-4-bromanthraquinone-2-sulfonic acid, a wavelength of 650'n is used as a starting material.
The molar extinction coefficient at ff1 is 1. O/ /ls-m
A method for producing 1-amino-4-bromanthraquinone-2-sulfonic acid using 1-aminoanthraquinone of o1 or less.