CH200260A - Process for the production of a vat dye. - Google Patents

Description

  

  Process for the production of a pebble dye.
EMI0001.0002
    According to the main patent, a valuable vat dye is obtained if m-toluidine is reacted with a pyrazinoanthraquinone of the structure in which g is a residue which is split off during the reaction.



  Halogen atoms, hydrogyl, mercapto, amino, alkoxy and alkyl mercapto groups, as well as quaternary ammonium groups, can be used as the removable radical g.



  It has now been found that a valuable vat dye is also obtained if the pyrazinoanthraquinone described in the main patent is reacted with m-bromoaniline. The reaction can be carried out by heating the compound described above in excess m-bromoaniline or by heating the calculated amounts of the reaction participants in a suitable solvent, for example in the presence 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 reddish orange tones, which have excellent real working properties.



  <I> Example 1: </I> 3.2 parts of Pz-chlorogy-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 1.75 parts of m-bromoaniline in 40 parts of nitrobenzene until the evolution of hydrochloric acid has ended. When the reaction mixture cools, the dye separates out in orange needles; it is kept pure by suction and steaming.



  He dyes cotton from a brown vat with a strong reddish orange.



       Example <I> 2: </I> 10 parts of Pz-dioxy-1,2-pyrazinoantbrachinone are heated to 180-190 ° C. with 2 parts of zinc chloride in 50 parts of nitrobenzene, then 10 parts of m-bromoaniline are slowly introduced and this continues heated until no more dioxypyrazinoanthraquinone can be detected. Then it is allowed to cool, suctioned off and worked up as described in Example 1. The same dye is obtained in very good yield.



       Example <I> 3: </I> A mixture of 10 parts of Pz-oxyamino-1,2-pyrazinoanthraquinone (can be prepared by introducing ammonia into a solution of Pz -Chloroxy-1,2-pyrazinoanthraquinone in nitrobenzene; red-brown powder that dissolves in sulfuric acid with a brown color and forms a yellow sulfate), 10 parts of m-bromoaniline and 100 parts of nitrobenzene are heated to the boil for several hours and it is worked after cooling down. The dye obtained in this way corresponds to that obtained in Example 1.



  The dye is also obtained if, instead of Pz-ozy-amino-1,2-pyrazino-anthraquinone, the correspondingly obtainable Pz-oxy-methylamino-1,2-pyrazino-anthraquinone (yellow-red needles in sulfuric acid with yellow-red color are soluble and form a yellow sulfate), or the Pz-Oxy-merkapto-1,2-pyrazinoanthracbinon (obtainable by reacting Pz-chlorooxy-1

  2-pyrazinoanthraquinone with alcoholic sodium sulfide and conversion of the sodium mercaptide thus obtained into the free mercaptan by treatment with hydrochloric acid; red-brown powder, which dissolves in alkalis with a red-violet color) or the thioether which can be prepared from it by methylation with dimethyl sulfate, or Pz-oxy-ethoxy-1,2-pyrazinoanthraquinone (obtainable by heating Pz-chloroxy-1 ,

  2-pyrazinoanthraquinone with alcoholic sodium hydroxide; yellow needles made from glacial acetic acid) or the Pz-oxy-pyridinium chloride of 1,2-pyrazinoantbrachinone of probably the following composition
EMI0002.0044
    obtained by gently warming Pz-chloro-oxy-1,2-pyrazinoanthraquinone with pyridine in the form of pale yellow, water-soluble needles.

 

Claims (1)

PATENT APPROPRIATE Process for the production of a vat dye, characterized in that m-bromoaniline with a pyrazino-anthraquinone of the structure EMI0002.0055 converts, in which ä means a radical which is split off during the reaction. The new dye dyes cotton from brown güpe in strong reddish orange tones, which have excellent fastness properties.