CH122760A - Process for the production of a new indigoid dye. - Google Patents

Description

  

      Process for the production of a new indigolden dye. It has been found that a new indigoid dye is obtained if the 6-chloro-o-toluidine (CHs: NH2 Cl -1: 2:

   6) by diazotizing, combining the diazo compound with an alkali oxanthogenate, treating the coupling product with a caustic alkali and condensation of the resulting compound with an alkali salt of a monohaloacetic acid, converted into 2 - methyl - 3 - chloro -1 - phenylthioglycolic acid,

   in a second phase these cyclized by treatment with condensing means to 6-chloro-7-methyl-3-oxy thionaphten and in a third phase 1 mol. 6-chloro-7-methyl-3-oxythionaphten with the action product of 6 -Chlor-7-methyl-3-oxythionaphthene condensed onto an aromatic nitroso compound.

   The new dye forms a crimson-red powder that dissolves in sulfuric acid with a yellowish green color. It dyes cotton from a green-yellow hydrosulphite vat in bright crimson-red tones with excellent washing and chlorine fastness.

           Example: 71 parts of 6 - chloro-o-toluidir (CHs: NH2 C1-1: 2: 6) are diazotized in a known manner and poured into a <B> 700 </B> hot solution of 90 parts of potassium hydroxide and 80 Share soda entered.

   When the evolution of gas has ended, the mixture is left to cool, extracted with ether, and after the ether has evaporated, it is saponified with 125 parts of 400 B6 sodium hydroxide solution and 300 parts of fuel on a reflux condenser and in the same solution with 70 parts of chloroacetic acid dissolved in 84 parts of 40 B6 sodium hydroxide solution and water , condensed. The fuel is distilled off, left to cool and acidified with hydrochloric acid. The precipitated 2-methyl-3-chlorophenylthioglycolic acid is filtered and dried.

   Recrystallized from dilute fuel, it forms white needles with a melting point of 104 '.



  28 parts of this product are now dissolved in ten times the amount of phosphorus trichloride; 22 parts of aluminum chloride are then added and the mixture is slowly heated to 60 to 65. With vigorous evolution of hydrogen chloride, the liquid takes on a red-brown color. The excess of phosphorus trichloride is then distilled off in vacuo and the residue is discharged into water and ice to decompose the phosphorus and aluminum compounds. The reaction product is filtered and purified by dissolving it in dilute alkali, filtering and precipitating with acid.



  The 6-chloro-7-methyl-3-oxythiorraplrten forms a colorless body, which crystallizes from dilute acetic acid in beautiful needles with a melting point of 102 to 10311. It is sparingly soluble in alcohol, ether, ligroin, and benzene; it can easily be obtained in a pure state by distillation with steam.



       19; 8 parts of 6-chloro-7-methyl-3-oxythionaph- th are dissolved in 100 parts of 12% sodium hydroxide solution, heated to 40 to 50 ° and with a solution of 16.5 parts of p-nitrosodimetlrylaniline in 100 Share fuel.

   Condensation occurs immediately and the thick pulp which precipitates is filtered and washed out with hot water until the filtrate is colorless. The new p-dimethylarnirroanil of 6-chloro-7-methyl-thionaphtenquinone dissolves in hot benzene with a red color and crystallizes in beautiful green, shiny needles with a melting point of 256 to 257 0 when it cools.



  33 parts of this anil and 19.8 parts of 6-chloro-7-methyl-3-oxythionaphterr are now suspended in 400 parts of alcohol and heated to the boil for a few hours. The new dye deposited in good yield is filtered, washed and dried.

 

Claims (1)

PATENT CLAIM: Process for the production of a new indigoid dye, characterized in that the 6-chloro-o-toluidine (CH: r: NH2: Cl = 1: 2: 6) by diazoing, combining the diazo compound with an alkali metal oxanthate, treating the coupling product with a caustic alkali and condensing the resulting compound with an alkali metal salt of a monohaloacetic acid into 2-methyl-3-chloro-1 -phenylthio- glycolic acid transferred, in a second phase this cyclized to the 6-chloro-7-methyl-3-oxythionaphthene by treatment with condensing agents and in a third phase 1 mol. 6-chloro-7-methyl-3-oxythiorraphthene with the product of action condensed from 6-chloro-7-nrethyl-3-oxythionaphtene on an aromatic nitroso compound. The new dye forms a red powder that dissolves in sulfuric acid with a yellowish green color. It dyes cotton from the green-yellow Hydrosirlfit küpe in bright carmoisine-red tones with excellent wash and chlorine fastness.