DE1032452B - Process for the preparation of 4-amino-5'-bromoanthraquinone-2, 1 (N) -1 ', 2' (N) -benzolacridone - Google Patents

Description

Process for the preparation of 4-amino-5'-bromoanthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone The for the preparation of 4-amino-5'-bromo-anthraquinone-2,1- (N) -1 ', 2' (N) - benzolacridone required 1-anilido-4-amino-2'-carboxy-4'-halo-anthraquinone-3-sulfonic acid was previously according to the scheme obtained by reacting 1-bromo-4-amino-anthraquinone-3-sulfonic acid with 2-amino-5-halobenzoic acid. In this way, the 4-amino-5'-chloroanthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone was prepared and the corresponding, hitherto unknown bromine derivative can also be obtained. In both cases one is therefore dependent on the use of technically difficult to obtain 2-amino-5-halo-benzoic acid. It is also known from German patent 560 236 that anthraquinone-2,1-benzacridone can be halogenated.

It has now been found that 1 anilido-4-amino-2'-carboxy-4'-bromo-anthraquinone-3-sulfonic acid can be obtained more advantageously if the readily available, already known 1-anilido-4-amino-2'-carboxy-anthraquinone-3-sulfonic acid in strong sulfuric acid, weak oleum or chlorosulfonic acid at low temperature treated in the presence or absence of catalysts with the calculated amount of bromine.

Since the hydrogen bromide formed during the bromination by the Sulfuric acid is immediately oxidized, only 1 gram atom of bromine is required for bromination required per mole of starting material.

It was surprising that the bromination was unambiguous and exclusive leads to a monobromo derivative, which is known to occur in the bromination of anthranilic acid is not the case. This uniform course of the bromination has the advantage that no undesired by-products arise in the subsequent acridone ring closure.

For conversion into the 4-amino-5'-bromo-anthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone by the process according to the present invention 1 anilido-4-amino-2'-carboxy-4'-bromo-anthraquinone-3-sulfonic acid in chlorosulfonic acid, strong sulfuric acid or weak oleum is heated to 50 to 100 ° C. This causes ring closure and splitting off of the sulfo group. The acridone ring closure can also be carried out together with the bromination in one operation. In this procedure, it is advisable to increase the sulfuric acid concentration after the halogenation has ended, e.g. B. by adding oleum. The acridone can either be isolated as sulfate or by further diluting the melt with water.

The economy of this process is based not only on the replacement of the expensive 5-halo-anthranilic acid by the cheaper anthranilic acid, but there is also a smaller excess of the latter in the dyestuff condensation with 1-bromine- 4-amino-anthraquinone-3-sulfonic acid required. EXAMPLE 1 137 kg of 1-anilido-4-amino-2'-carboxy-anthraquinone-3-sulfonic acid are slowly introduced into 1370 kg of 98% sulfuric acid at 10 to 15 ° C. in order to avoid clumping. When the solution is complete, 26 kg of bromine are gradually added at the same temperature over the course of 4 hours. Since the bromination is carried out using only half a mole of bromine, escape of hydrogen bromide must be prevented and the apparatus must be closed. A slight overpressure is created during the bromination. After the addition of the bromine, the temperature is allowed to rise to 20 to 25 ° C. and the mixture is stirred until the bromate atmosphere that protrudes from the bar has disappeared and no more hydrogen bromide can be detected, which is the case after about 10 hours. Finally, neither bromine nor hydrogen bromide must be present, and a sample should only smell of SO,.

The finished bromination product is pressed onto 37001 water and 301 Bisulfite, heated to 95 to 100 ° C for 1 hour and pressed or peeled off hot. Possibly can also be diluted with another 20001 water before vacuuming. The Nutschkuchen is with 50 ° C warm 2% hydrochloric acid until the run-off is clear and removed washed the sulfuric acid. Finally, it is covered once with cold water and dried at 100 ° C.

1-Anilido-4-amino-2'-carboxy-4'-bromo-anthraquinone-3-sulfonic acid is obtained in violet-red needles, which are clear blue in water, in concentrated form Dissolve sulfuric acid bluish green and in sulfur boric acid green. She dyes wool in clear blue tones with good lightfastness.

Yield: 156 kg of 1-anilido -4-amino -2 '-carboxy-4'-bromo-anthraquinone-3-sulfonic acid. 25.9 kg of dry 1-anilido-4-amino-2'-carboxy-4'-bromo-anthraquinone-3-sulfonic acid are introduced into 200 kg of 2% oleum without cooling. After the entry there should still be free SO . Then it is heated to 100 ° C. The sulfo group is split off while the solution turns brown, and acridone ring closure occurs. The temperature is held for about 1 hour until a sample that has been worked up in water shows no runoff when washed with hot water, neither neutral nor ammoniacal. The well-crystallized brown sulfate is then deposited at 90 to 100 ° C. by adding 80 liters of water. At 25 ° C is suction filtered and washed with 70% sulfuric acid until the runoff is clear. The filter cake is washed neutral and dried.

It can also be put directly on water immediately after it has been put down are given.

Yield: 19.3 kg of 4-amino-5'-bromo-anthraquinone-2,1 (N) -1 ', 2' - (N) -benzolacridone. Bromine content 18.9%; calculated 19.10 / bromine.

The amino-bromo-acridone is sparingly soluble in organic solvents. When recrystallizing from nitrobenzene, it is obtained in blue-black needles. Solution color in concentrated sulfuric acid: orange brown, referring to the addition of formaldehyde or boric acid changes only slightly. It dyes cotton from a purple vat in blue Tones. Example 2 The bromination of 1-anilido-4-arnino-2'-carboxyanthraquinone-3-sulfonic acid is carried out exactly as described in Example 1, only at the end of the Removal of small amounts of bromine or hydrogen bromide for short S 02 or a dry one Air flow passed through the melt. Then the melt with 740 kg 200 / @ according to Added oleum, so that about 1% oleum is present before heating. the The slightly smoking solution is now heated to 100 ° C and this temperature for 1 hour held long. At 90 to 100 ° C, the melt is diluted with 8201 water and cooled to 25 ° C and the well-crystallized 4-amino-5'-bromo-anthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone away. It is washed with 700% sulfuric acid. The nutsch cake becomes neutral washed and dried.

Yield: 110 kg of 4-amino-5'-bromo-anthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone.

Claims (1)

Claim: Process for the preparation of 4-amino-5'-bromoanthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone, characterized in that 1-anilido-4-amiDo-2'-carboxy -anthraquinone-3-sulfonic acid in strong sulfuric acid treated with the calculated amount of bromine and the resulting 1-anilido-4-amino-2'-carboxy-4'-bromo-anthraquinone-3-sulfonic acid by heating in strong sulfuric acid in the 4- Amino-5'-brozuanthraquinone-2,1 (N) -1 ', 2' (N) -benzolacridone converted, publications under consideration: German Patent No. 560 236. When the application was announced, a coloring table was laid out.