CH274425A - Process for the preparation of a metal-containing monoazo dye. - Google Patents

Description

  

  Process for the preparation of a metal-containing monoazo dye. It was found that a valuable metal-containing monoazo dye can be obtained by using a moiioazo @ b-substance of the formula
EMI0001.0007
    chromium-donating agents can act under conditions in which the alkyl group of the -O-alkyl radical in the o-position to the azo group is split off.



  The new metal-containing dye is a dark-colored substance, which see in ver dilute sodium carbonate solution with purple and in conc. Sulfuric acid dissolves with a red color and colors wool in the sulfuric acid bath in even, genuine pale tones.



  The ionoazo dyes which serve as starting materials in the present process and correspond to the above formula can be prepared by adding a diazotized 2-alkoxy-5-methoxy-1-aminobenzene-4-sulfonic acid diethviamide with 2-ozynaphthalene-6- sulfonic acid couples.

   The alkoxy group in the 2-position of the diazo component preferably contains only a few, for example 1 to 4 carbon atoms. The monoazo dye obtainable from diazoated in 2,5-diniethoxy-1-aniinol) enzol-4-sulfonic acid diethylamide has proven to be a particularly two-dimensional starting material for the present process.



  The diazotization of the 2-alkoxy-5-metlioxy-1-aniinobenzene-4-sulfonic acid diethylamide can be carried out in a conventional manner known per se, e.g. B. with the help of sodium nitrite and hydrochloric acid.

   The coupling of the diazo compound with the 2-ozynaphthalene-6-sulfonic acid is carried out in an alkaline, for example sodium carbonate alkali metal, sodium chloride. If necessary, the coupling can also be carried out in the presence of suitable solvents such as alcohol or pyridine.



  The ionoazo dyes used as starting materials in the present process can, if desired, be isolated from the coupling mixture and freed from impurities. In general, however, the coupling compound as a whole and an intermediate separation can be used for treatment with the chromium donating agents.

    Usually is. it is necessary here to adjust the coupling mixture to the pH value favorable for this reaction before carrying out the reaction with your ehroinabY @ ebenden agent (this means to a weak mineral acid reaction.



       In the present process, the salts of trivalent chromium such as chromium fluoride, chromium sulfates, chromium acetate and chromium formate are particularly suitable as ear-releasing agents. The treatment with the chromium-releasing agents takes place under conditions under which the alkyl group of the -0-alkyl radical in the o-position to the azo group is split off.

    This cleavage with simultaneous formation of the complex chromium compounds can be carried out according to a method known per se by treating with the chromium-releasing agent, e.g. B. with chromium formate or chromium sulfate in aqueous, preferably mineral acid 1Tedium under pressure at elevated temperature, e.g. B. temperature between 110 and 140 makes.

      <I> Example: </I> 28.8 parts of 2,5-dimethoay-1-aminobenzene-4-sulfonic acid diethylamide. conventionally diazotized in the presence of 46 parts of 30% hydrochloric acid with 7 parts of sodium nitrite. The solution of the diazo compound is stirred into a mixture, cooled to 10, of 23 parts of? -Oxynaplitha.lin-6-sulphonic acid and 40 parts of anhydrous sodium- <RTI

   ID = "0002.0026"> Add earbonate in -100 parts of water. The separation of the resulting dye is completed by adding sodium chloride. The dye is filtered off. Created. G-etroclznet is a dark colored substance, which looks in dilute sodium carbonate solution with red and in conc. Sulfuric acid dissolves with a violet color and dyes wool from acidic baths in red tones.



  This dye can, advantageously without prior drying, be converted into the complex chromium compound. For this purpose, the paraffin paste obtained according to the above information is stirred with 1000 parts of hot water and 10% sulfuric acid is added until it has a very weak mineral acid reaction. After adding an amount of chromium sulfate (Cr, [SO.F] ;; l containing 5.7 parts of chromium), the reaction mixture is heated to 128 to 130 in the leaded stirred autoclave and stirred at this temperature for 20 hours .

   Most of the resulting chromium compound is obtained. It is filtered off and washed up with 5% sodium chloride solution. The FilterrVielistand is dissolved in 200 parts of water at 55 to 60 with the addition of 16 parts of 30% sodium hydroxide solution and evaporated to dryness in a vacuum.

 

Claims (1)

<B> PATENT CLAIM </B> -. Process for the production of a metal-containing monoazo dye, thereby-disgusting) - draws, that one on a. Monoazo dye of the formula EMI0002.0068 chromium-donating agents can act under conditions in which the alkyl group of the -0-alkyl radical in the o-position 7.1U 'azo group is split off. The new metallialti "e dye is a dark colored substance, which see in diluted sodium carbonate solution with violet and in conc. Sulfuric acid dissolves with a red color and dyes wool from sulfuric acid in a bath in uniform, elaborate, lxlane tones. UNTTRAN ',: PRCCHE 1. Process according to patent claims, characterized in that one starts from such #tonoazo dyes in which. the -0- Alb-1 group located in the o-position to the azole group contains 1 to 1 carbon atoms. . 2. Process according to patent claim and dependent claim 1, d <idui-cli characterized in that inan of the monoazo dye of the formula EMI0002.0106 borrows. 3. The method according to patent claim, characterized in that salts of the trivalent clirome are chosen as the chromium-releasing 1Iittel. -I. Process according to patent claim, characterized by the fact that the treatment with the chromium-releasing agent is carried out in an aqueous medium and under pressure at an elevated temperature.