CH196352A - Process for the production of a vat dye. - Google Patents

Description

  

  Process for the production of a liquid dye. It has been found that a valuable vat dye is obtained if m-toluidine with a pyrazinoanthraquinone of the structure
EMI0001.0007
    converts, in which X is a radical which is split off during the reaction.



  The residues X that can be split off are Ha. logen atoms, hydroxyl, mercapto, amino, alkoxy and alkyl mercapto groups, and quaternary ammonium groups. The reaction can be carried out by heating the compound described above in excess m-toluidine 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 sulfate may be advantageous here.



  The new dye dyes cotton from yellow-brown vat in strong scarlet shades that have excellent fastness properties. <I> Example 1: </I> A mixture of 3.2 parts of Pz-chloroxy-1,2-pyrazinoantbrachinone (obtainable from Pz-dioxy-1,2-pyrazinoanthraquinone by heating with phosphorus oxychloride in nitrobenzene, yellow-brown needles with a melting point of 268 C), 1.1 parts of m-toluidine and 40 parts of nitrobenzene to the boil until no more hydrogen chloride escapes.

   When the reaction mixture cools, the dye separates out in red-brown needles. It is suctioned off and freed from adhering nitrobenzene using steam. He dyes from yellow-brown liüpe tree wool in strong scarlet shades.



  <I> Example 2: </I> 10 parts in toluidine are slowly introduced into a mixture, heated to 180-190 ° C., of 10 parts of Pz-dioxy-1,2-pyraziuoantlirquinone, 2 parts of zinc chloride and 50 parts of nitrobenzene the mixture continues to heat until no more Dioxypyi-azinoantliracliinori can be detected.

   Then it cools down, sucks off the dye and works up as described in Example 1. He keeps the dye in very good yield. Example <I> 3:

  </I> A mixture of 10 parts of Pz-oxymercapto-1,2.pyi-azinoantlii-achinori (l) ei-stellb, ii # by reacting Pz-Chloi-oxy-1,2-pyrazino-anthraquinone with alcoholisehein 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) and 10 parts of m-toluidine are heated to boiling;

   hydrogen sulfide escapes in the process. If the initially yellow-brown color of the solution does not shift any further to red, the mixture is allowed to cool, the dye is suctioned off, washed with alcohol and dried.



  If, instead of Pz-oxy-mercapto-1,2-pyrazinoanthi-achinoris, the thioether obtained therefrom by methylation with diniethyl sulfate or the sulfoxide which can be prepared from this by oxidation with ammonium persulfate in sulfuric acid, the same dye is obtained.



  The dye is also obtained if Pz-oxy-aniino-1,2-pyi # azinoantlii aehinon (obtainable by introducing ammonia into a solution of Pz.Chloroxy-1 heated to about 150C) , 2.pyrazinoanthracliinor) inI \ titrobenzene;

      red-brown powder that dissolves in sulfuric acid finitely brown in color and forms a yellow sulphate) or Pz-oxy-ethoxy-1,2-pyrazinoanthraquinone (obtainable by heating Pz-Chloi-oxy-1,2-pyrazii) oaiithrachirion with alcoholic iialium hydroxide solution; yellow needles from glacial acetic acid).



  <I> Example </I> 5 parts of the pyridinium compound obtainable by gently heating Pz-cliloroxy-1,2-pyrazinoantbrachinone with pyridine, probably of the following composition
EMI0002.0062
    (weakly colored, water-soluble needles) are heated to boiling in 51) parts of nitrobenzene with 2 parts of in-toluidine for about 1 hour. The dye is separated off in the usual way. The reaction takes place correspondingly more slowly, even at lower temperatures.

 

Claims (1)

<B> PATENT CLAIM: </B> Process for the production of a vat dye. characterized in that one m-Toluidiu with a pyrazirioanthraquinone of the structure EMI0002.0070 converts, in which N is a residue which is split off during the reaction. The new dye dyes from yellow-brown hüpe cotton in strong scarlet tones, which have excellent authenticity properties.