SU31006A1 - Method for preparing mezodichlorantracene and anthraquinone beta monosulfonic acid - Google Patents

Description

It is known that in the production of p, monosulfonic acid of anthraquinone, up to 50% of unreacted anthraquinone remains, and, consequently, there is an incomplete use of the latter in each individual operation; up to 10% of anthraquinone disulfonic acid is always formed together with monosulfonic acid; When sulphonating anthraquinone under such conditions, a high temperature is required up to 140% and the use of high purity anthraquinone up to 93-99J%.

In the proposed method for the preparation of mesodichlorantracene-- and p - monosulfonic acid of anthraquinone, anthracene is chlorinated in o-dichlorobenzene or in a eutectic mixture of o and p-dichlorobenzene, boiling in a temperature range of 140-170 °, due to which the meso-dichloro-transcense phase reaches 90% , and the product has great purity.

The preparation of p - monosulfonic acid of anthraquinone from the obtained mesodichloranthracene is carried out without isolation of intermediate compounds. As is known1, the method is sulfonated1 in a solution of nitrous benzene with oleum with exactly 1414th amount of sulfuric anhydride required for sulfonation.

The oxidation of the resulting α-monosulfonic acid of mezodichlorantracene is carried out with diluted HNOs in the same apparatus directly after the distillation of nitrobenzene with water vapor; the anthraquinone formed with p-monosulfuric acid is released in high purity as the sodium salt in the usual manner. The yield of the sodium salt of p-sulfonic acid anthraquinone is almost theoretical, calculated as mezodichlorotranscene.

The sodium salt of p - monosulfonic acid of anthraquinone gives, under proper processing conditions, almost quantitatively, alizarin No. 1 in a very pure form.

Example 1. 89 g of 93% anthracene are suspended in 200 g of eutectic mixture of o- and p-dichlorobenzene, boiling in the range 140-170, and with stirring, dry chlorine gas is introduced to a total weight of 37-39 g with this calculation so that after removal of the entire reaction HC1, the weight gain is 32-34.5 t.

After twelve hours, crystalline mezodichlorantracene is filtered off, well drained and

washed with alcohol until complete removal of dichlorobenzene. The yield of mezodichlorantracene reaches up to 90% of the theoretical. The solvent can be re-applied to chlorinate the fresh portion of aatpaueHa either directly or after distillation. To 123.5 g of mezodichlorantracene (crude with temp, melt,) suspended in 400 g of Nitrobenzene, are added dropwise 205, 2 g of oleum with 19.5% sulfuric anhydride over two hours at a temperature of 10-12 ° After adding the total amount of oleum, it is stirred for another 4 hours. The sulfuration mass is then poured into 640 g of crushed ice and the nitrobenzene is distilled off with water vapor. 63 cm 32.5% HNO3 is introduced within one hour into the resulting suspension p - sulfonic mesodichlorantracene at the boiling point of the mixture. By the end of the heating, almost everything goes into solution with a brownish-yellow color. Then filtered from a small precipitate and the filtrate is neutralized at boiling with chalk. The precipitated gypsum is boiled and from the combined filtrates at boiling it is separated with CaCoz soda, which is filtered, and the filtrate is evaporated to a small volume. After a twelve hour period, the precipitated sodium salt of p-sulfonic acid anthraquinone is dried. The yield of the sodium salt of p-sulfonic acid of anthraquinone reaches g, which is 93-94% of the theoretical, calculated as meso-dichlorotracene.

Example 2. To 247 gmesodichlorantracene with temp, melting. 209, suspended in 800 g of nitrobenzene, is added by

drops within two hours 400g of oleum with 20% content of sulfuric anhydride at a temperature of 12-159. After adding the total amount of oleum, it is stirred for another 4 hours. Then, 1200 g of crushed ice are gradually added to the sulphurization mass and distilled water from the nitrobenzene is removed from the same vessel. To the resulting suspension of p-sulfonic acid, mezodichlorantracene, at a temperature of 105-108 °, 64 cm HNOs beats are added over one hour. at. 1,364. After the addition of nitric acid, it is heated for another 4-5 hours, and the oxidation is quantitatively completed; the clear, hot solution neutralizes with chalk and the p-sulfonic acid of anthraquinone is isolated as the sodium salt in the usual way. The output is quantitative. In alkaline oxidative melting, the resulting sodium salt — sulfonic acid of anthraquinone — forms alizarin No. 1 for 28 hours in a yield of 85–8.1% in very pure form.

The subject matter of the invention.

,one. The method of producing mesodichlorantracene by the action of dry chlorine on anthracene, characterized in that the chlorine of anthracene is produced in dichlorobenzene or eutectic mixture of o- and p-dichlorobenzenes boiling from 140 to 170.

2, Use obtained by the method indicated in paragraph 1 of mesodichloranthracene to obtain p-monosulfonic acid of anthraquinone without isolation of intermediate compounds by a known method.