CH200268A - Process for the production of a vat dye. - Google Patents

Description

  

  Process for the production of a vat dye. According to the main patent, a valuable vat dye is obtained if m-toluidine with a pyrazinoanthraquinone of the structure
EMI0001.0006
    converts, in which X is a radical which is split off during the reaction.



  Possible residues X which can be split off are halogen atoms, hydroxyl, mercapto, amino, alikoxy and alkyl mercapto groups, and quaternary ammonium groups.



  It has now been found that if the pyrazinoanthraquinone described in the main patent is reacted with 2,6-dichloro-3-toluidine, a valuable overdye is also obtained.



  The reaction can be carried out by heating the compound described above in excess 2,6-dichloro-3-toluidine or by heating the calculated amounts of the reaction participants in a suitable solvent, for. B. in the present. of nitrobenzene. The addition of a condensing agent such as zinc chloride, boric acid or an alkali metal bisulfate may be advantageous here.



  The new dye dyes cotton from a brown vat in strong orange tones that have excellent fastness properties.



  <I> Example </I> 3.2 parts of Pz-chloroxy-1,2-pyrazinoanthraquinone (obtainable from Pz-dioxy-1,2-pyrazinoanthraquinone by heating with phosphorus oxychloride in nitrobenzene, yellow-brown needles with a melting point of 268 C) are boiled with 1.8 parts of 2,6-dichloro-3-toluidine in 40 parts of nitrobenzene until the development of hydrochloric acid has ended.

   When the reaction mixture cools, the dye separates out in orange-brown needles; by suction and steaming it will keep it pure.



  It dyes a strong orange color from brown güpe cotton.



       Example <I> 2: </I> 10 parts of Pz-dioxy-1,2-pyrazinoanthraquinone are heated to 180-190 ° C. with 2 parts of zinc chloride in 50 parts of nitrobenzene, then slowly 10 parts of 2,6-dichloro-3 -toluidine entered and continued to heat until no more dioxypyrazinoanthraquinone can be detected. Then leave it cold, vacuum it and work it up as described in example 1. The same dye is obtained in very good yield.



  <I> Example 3: </I> 10 parts of Pz-oxy-amino-1,2-pyrazino-anthraquinone (obtainable by introducing ammonia into a solution of Pz - heated to <B> 150 '</B> C) Chlorine-oxy-1,2-pyrazino-anthraquinone in nitrobenzene; red-brown powder that dissolves in sulfuric acid with a brown color and forms a yellow sulfate), 10 parts of 2,6-di-chloro-3 = toluidine and 30 parts of nitrobenzene to simmer for about 1 hour.

   After cooling, the dye that has separated out is suctioned off, washed with alcohol and dried.



  The dye is also obtained if the Pz-Ogy-methylamino-1,2-pyiazinoanthraquinone is used in place of the Pz-oxyamino-1,2-pyrazinoanthraohinone (which can be produced in a corresponding manner by using methylamine on ammonia ;

            yellow-red needles. which are soluble in sulfuric acid with a yellow-red color and form a yellow sulfate), or Pz-Oxy-mercapto-1,2-pyrazinoanthraquinone (produced by reacting Pz - chloroxy - 1,2 - pyrazino-anthraquinone with alcoholic sodium sulfide and conversion the sodium mercaptide thus obtained into the free mercaptan by treating with hydrochloric acid;

   red-brown powder, which dissolves in alcohol with a red-violet color) or the thioether obtainable from it by methylation with dimethyl sulfate or the Pz-oxy-ethoxy-1,2-pyrazino-anthraquinone (for example obtainable by heating Pz - chloroxy - 1,2 - pyrazino-anthraquinone with alcoholic potassium hydroxide solution;

      yellow needles made of glacial acetic acid) or the pyridinium chloride of the probable composition, obtainable from Pz - chloroxy - 1,2 - pyrazinoanthraquinone by gentle heating with pyridine
EMI0002.0078
    (Pale yellow colored, water-soluble needles).

 

Claims (1)

<B> PATENT CLAIM: </B> Process for the production of a vat dye, characterized in that 2,6-dichloro-3-toluidine with a pyrazino-anthraquinone of the structure EMI0002.0086 converts, in which X is a radical which is split off during the reaction. The new dye dyes cotton from brown güpe in strong orange tones, which have excellent fastness properties.