CH226633A - Process for the preparation of the leuco-sulfuric acid ester of a vat dye of the anthraquinone series. - Google Patents

Description

  

  <B> Additional patent </B> to main patent no., 222255. -Process for the production of the leuco-sulfuric acid ester of a nub dye of the anthraquinone series. The subject of this patent is a process for the production of the LeukosGhweiel- acid ester of a vat dye of the anthraquinone series, which consists in that the dye,

   that by coupling the diazotized 1-aminoanthraquinone with 1-benzoylacetylamino-4-benzoylamino-2. 5-dimethogybenzene is obtainable and is converted into the leuco-sulfuric acid ester by treatment with a reducing agent and an esterifying agent which provides sulfur triogide in the presence of a tertiary base.



  The conversion of the liquid dye into the leucosulfuric acid ester is carried out in the usual way, for example by treating the dye in the presence of a tertiary base, such as pyridine, and an esterifying agent which provides sulfur triogyd, for example chlorosulfonic acid or chlorosulfonic acid ester, with a metal for example with copper or iron.

           For working up, the reaction mixture is expediently added to a solution of sodium, carbonate or sodium hydrogen or ammonia in water, in a suitable manner, for example by distillation in vacuo, of the tertiary;

      Freed base and filtered off from the metal salts. The leuco-sulfuric acid ester formed can from the filtrate in the form of a salt, for example in the form of the sodium salt or potassium salt, through. Salting out with sodium chloride or potassium chloride can be obtained.

   The precipitated alkali metal salt of the leuco or sulfur cure ester is filtered off and a little sodium carbonate is added to increase the shelf life.

      <I> Example: </I> In 800 parts by weight of a pyridine fraction from the boiling point approximately. 125-126 C, 150 parts by weight of chlorosulfonic acid are run in with stirring and cooling and <B> 100 </B> parts by weight of the azo dye obtained by coupling dianotated 1-aminoanthraquinone with 1-benzoylacetylamino-4-benzoylamino are carried -2. 5-dimethoxybenzene is obtained, and 60 parts by weight of iron powder.

   Al on heats the reaction mass briefly to 40-50 C. As a result of the heat of reaction, the temperature rises to 60 C for a short time. After stirring for one hour, the esterification mixture is added to a solution of 230 parts by weight of sodium carbonate in 4000 parts by weight of water and the mixture is distilled free of pyridine in vacuo. After the distillation has ended, the ester that has separated out in the cold is filtered off,

   dissolves it in hot water and clears the iron slag mm. The filtrate and @Va: water are salted out with sodium chloride, the leuco @ sulfuric acid ester is sucked off in the cold and with. 2 parts by weight of sodium carbonate pasted. Acid oxidation gives the ester a brown with very good fastness properties both in substance and on the fiber.

 

Claims (1)

PATENT CLAIM: A process for the preparation of the leuco-sulfuric acid ester of a vat dye of the anti-liraeliinone series, characterized in that the dye obtained by xupping the dianotated 1-aminoanthraquinone with 1-benzoylacetylamino-4-benzoylamino-2.5- @ dimethoxybenzene is available by treatment with a reducing agent and an esterifying agent which provides sulfur trioxide in the presence of a tertiary base in the 1.tenkosch, vefelsäureester leads. By developing according to the processes customary for this class of dye, the new leukocyl acid ester produces a brown with very good fastness properties in substance as on the fiber.