SU19616A1 - The method of producing dioxynaphthalene mono- or polysulfonic acid from the corresponding amino-naphtholsulfonic acid - Google Patents

Description

The present invention relates to a process for the preparation of dioxivaphthalene mono or POA sulfonic acids from the corresponding aminonaphthal sulfonic acids.

Until now, dioxynaphthalene-sulfonic acids, and mainly 1: 8-dioxynaphthalene-4-sulfonic acid and 1-dioxynaphthalene-3 6-dnsulfonic acid (hromotrcane), were mainly produced by fusion with aqueous alkalis or by heating with aqueous oxides of alkaline earth metal with a corresponding content of nitrothrothrothrothroxane, and with alkali earth alkali metals or heated with alkaline earth metal oxides of the corresponding structure with neutral polyactephraxane, they were mainly produced by melting with aqueous alkalis or heated with alkaline earth metal oxides with a corresponding content of nitrophrothanol, and the corresponding structure with neutral polyactetne; DRP 67563, 68721, 69190, 67829, 71836, 80365, 75962, 77285i 80667), at which the heating was carried out to a sufficiently high temperature (above 200 °) and under considerable pressure (to 20 and above atmospheres). Acid methods known in the literature for the preparation of these compounds or use the very specific nature of the acid agent, such as, for example, the method described in DRP 109102, using acid salts of sulfurous acid, or used (only with respect to 1: 8 : 6- disulfonic acid (such amount of mineral acid, which is sufficient only to neutralize the salts of this acid and release it in the free state).

Now that autorgne has been found that dioxnaphthalene-3-hydroxy- or full-sulfonic acid can be easily obtained from the available amino naphthol-sulfonic acid by treating ayononapholo - “- monr- or aolysulfonic acid in an autoclave with sulfuric acid (conc.) At a temperature of 170-190 ° and not over 10 atmospheres, with the Czech Republic, the shortness of interaction (from 1–2 hours) is the point of keeping intact even the most mobile sulfo group. The advantages of such a method of obtaining these dioxinaphthnsulphonic acids are, in the opinion of the authors, that the reagents are less expensive to work, they are much more easily separated and the products are very high in their purity compared to the alkaline way of working.

Example 1. In an autoclave, coated on the inside with acid-resistant enamel or leaded, load 1000 t 1 8 amino-naphthol-3: 6 - disulfonic acid (BO / one), 3600 "water and 100" sulfuric acid at 66 ° Ve, after which the contents of the autoclave are heated for 2 hours at a temperature of 190 and prc pressure of 10 atgz. Then

the solution obtained after the reaction is concentrated by evaporation to the original volume, whereby chromotropic acid is released in a state of high purity with a yield of theoretical.

Instead of thickening, chromotropic acid can be partially or completely separated by salting it out with common salt in good yields.

Example 2. 300 a 1: 8-aminonaphthol-4-sulfonic acid (EO / o-th), 3000 g of water and 65 g of sulfuric acid at 66 ° Ve are charged to an autoclave. Heating in an autoclave at 178 ° and 8 atm. pressure lasts for 1 hour. After cooling the contents of the autoclave, precipitated in the crystalline

as 1: 8-dioxynaphthalene-4-sulfonic acid, and dried. Output up to 83 ° / o from theory. Up to 10 substances can be removed from the mother filter.

The subject of the patent.

A method for producing dioxynaphthalene-ammonium or polysulfonic acid from the corresponding aminonaphthol sulfonic acid, characterized in that the amino-naphthol-ammonium or polysulfonic acid is heated under pressure for not more than 2 hours at a temperature below 200 ° C with diluted sulfuric acid of 3 to 5 in such quantity , so that at the end of the reaction the mixture has a distinct mineral acid reaction.