CH137657A - Process for the preparation of a valuable vat dye. - Google Patents

Description

  

      Process for the preparation of a valuable itupine dye. The main patent describes a process for the preparation of a valuable vat dye, in the case of the aminodibenza throne, which can be obtained through the elution of the mononitrodibenzanthrone produced by nitrating dibenz anthrone,

      is condensed with an anthraquinone which is negatively substituted in the 1- position.



  It has now been found that a similar valuable vat dye is obtained if aminodibenzanthrone, which can be obtained by reducing the blononitrodibenzanthrone formed by nitrating dibenzanthrone, with a negatively substituted dibenzanthrone in the Bz-2 position, :

  which can be produced, for example, by nitrating dibenzanthrone or by reduction, diazotization and reaction with halogen compounds according to Sandmeyer from the nitrodibenzanthrone obtained by nitrating dibenzanthrone, condenses.

   The condensation is expediently carried out in high-boiling solvents or diluents, and acid-binding agents can also be added here. In many cases the application is:.; of catalysts advantageous, as which, for example, mixtures of sodium acetate and copper salts can be used.



  The new vat dye is a black powder; it is soluble in concentrated sulfuric acid with a violet color and dyes cotton from a blue vat in black, exceptionally real shades.



       Example <I> 1 </I> 47 parts of aminodibenzanthrone and 50 parts of mononitrodibenzanthrone are suspended. 30 parts of sodium acetate and 10 parts of copper acid in 2000 parts of nitrobenzene, boil for 24 hours with vigorous stirring, suck off hot and work up in the usual way.

   Instead of mononitrodibenzanthrone, you can also use the equivalent amount of monahalo @ gendibenzanthrone, obtained from dibenzanthrone by nitration, reduction, diazotization and reaction with halogen compounds according to Saadmeyer.



  The aminodibenzanthrone can be produced during the reaction from the corresponding nitro compound and a reducing agent, for example hydrazine hydrate or sulfur.

   If the aminodibenzanthrane is to be condensed with nitrodibenzauthrone, the procedure can be that only nitrodibenzanthrone is used and a sufficient amount of reducing agent is added to reduce only half of the titrodibenzanthrone present.



  Example 2: 500 parts of i \ itrodibenza.nthron (shown in accordance with German Patent No. 402,641) are mixed with 10000 parts of nitrobenzene with 85 parts of 100% hydrazine hydrate with stirring slowly heated to the boil and kept boiling as long as ammonia escapes. Then 10 parts of copper oxide and 250 parts of potash are added and the mixture is boiled with vigorous stirring until the dye has formed.

   It is filtered off with suction, washed with dilute hydrochloric acid and water and dried.

 

Claims (1)

PATENT CLAIM: A process for the production of a valuable vat dye, characterized in that aminodibenza.nthrone, which can be obtained by reducing the mononitrodibenzanthrone produced by nitrating dibenzanthrone, with a dibenzanthrone negatively substituted in the Bz-2 position, condensed. The new vat dye is a black powder; it is soluble in concentrated sulfuric acid with a violet color and dyes cotton from a blue vat in black, exceptionally real shades. SUBClaims: 1. Process according to patent claim, characterized by that the condensation is carried out in a high-boiling solvent. 2. Process according to patent claim, characterized in that the condensation is carried out in a high-boiling diluent. <3. Process according to claim, characterized in that the condensation is carried out in the presence of acid-binding agents. 4. The method according to claim, characterized in that the condensation is carried out in the presence of catalysts. 5. The method according to Palent claim, characterized in that such aminodibenzanthrone is used da.ss that was generated in the reaction mixture.