SU72484A1 - Method for producing alpha-hydroxyanthraquinone sulfonic acid - Google Patents

Description

U.-hydroxyanthropic SNS sulfonic acid, which are intermediates for the production of dyes, are obtained by melting the intratrain sulfonoses with alkaline earth metal oxides under pressure:; This method gives a small yield of the product, which, in this case, is difficult to separate from the initial sulphate shlots, which are not waxed in the reaction, and which are formed parallel to the shss-ianthrahione.

According to the proposed method, the axioanthiophenol acid can be obtained with almost quantitative yields by heating the corresponding disulfonic acids or their salts with water or wenary acid at a temperature of 230-290 ° C under pressure.

In contrast to the hydrolysis of sulfonic acids, which occur in concentrated sulfuric acid without pressure and usually leads to the replacement of the sulfo group with hydrogen to form unsulfated compounds, the hydrolysis into a weakly-layer medium under pressure produces hydroxy compounds.

The proposed method is simpler, does not require neutralizing agents, used with the known method, and gives a higher yield; more pure product. The resulting :: oxyanthraquinone sulfonic acid is easily salted out of the pea: cyoin solution with weak acid oxidation with hydrochloric acid.

Example 1. A 500 ml enameled autoclave with a capacity of 500 ml equipped with a stirrer was charged with 9.25 g of 1,8-anthraquinondisulfonic acid and 250 ml of 0.25% sulfuric acid. The contents of the autoclave are heated for 6 hours. at 2bO ° after cooling, the reaction mixture is salted out with sodium chloride with a weak acidification of the penis with hydrochloric acid, filtered off, washed with cold water and dried.

Yield; sodium: oxyate oxyanthraquinone sulfonic acid - 8 g, which is 98% of the theoretically possible.

By heating the sodium salt of the 1,8-anthraquinone disulfo new kiaiota in 0.25% sulfuric acid for 12 hours, at a temperature of 290 ° C, a sodium salt of oxyanthraquinone sulfonic acid is obtained, equal to 99% of the theoretically possible

Example 2. In equipped with a stirrer steel or enameled av79

: Toklaz approximately 500 ml is charged with 9.25 g of 1,6-anthrahiko11 disulfonic acid and 300 ml of water. After lagging at a temperature of 230-260 ° C for 6-12 hours. The reaction mixture was isolated by salting out with simultaneous acidification of the solution with hydrochloric acid and 8 g of the 1,6-oxyanthra / non-sulfonic acid sodium salt. Output .W0% of theoretically possible.

11-ed e: et and 3 about;) e 11 and

The method of obtaining v.-hydroxyanthracic sulfonic acids from anthrax: nondisulfonic acid acids, characterized in that the corresponding disulfonic acids are heated under pressure at a temperature of 230-290 ° C with water or with dilute sulfuric acid, after which the reaction product is separated by known techniques.