CH152251A - Process for the preparation of an aromatic monoaroyldiamino compound. - Google Patents

Description

  

  Process for the preparation of an aromatic nonoaroyldiamino compound. The industrial production of aromatic monoaroylamide compounds by reducing the corresponding aroylnitroaniino compounds is difficult in many cases because of the poor solubility of the nitro and amino compounds in water and the common organic solvents.



  It has been found that monoaroylamino compounds of the benzene and sodium phthalene series are obtained in a smooth reaction if the nitro aryl sulfamic acids obtainable by known processes are mixed with aroylating agents such as aromatic or aromatic aliphatic carboxylic acid halides treated and the sulfo group splits off by heating with dilute mineral acid.

    
EMI0001.0027
    The advantage of this process is that, firstly, there is no need to use solvents, since all the reaction stages can be carried out in aqueous solution thanks to the water-solubilizing sulfamine group, and secondly, the use of iron as the cheapest reducing agent. is permitted

       thirdly, the production of some monoaroyldiamino compounds is made possible, which are very difficult to obtain in other ways, as can be seen from the following examples:
EMI0002.0011
    According to the new procedure, these bodies are accessible from the corresponding nitroamines of the following formula:
EMI0002.0013
    Otherwise one would have to assume the following nitroamines, which are much more difficult to access:

    
EMI0002.0015
    The claimed process means an important technical advance for the production of monoarc> yldiamino compounds of the benzene and naphthalene series, which have gained importance as diazo components for azo dyes, especially those which are produced on the fiber.



  It is known to convert aromatic diamines, for example with oxalic acid, into aromatic monooxalyldiamino compounds and then with benzoylchloride into the corresponding aromatic ogalylbenzoyldiamino compounds. When treated with saponifying agents, however, the benzoyl radical is more or less saponified depending on the conditions.



       The present invention now relates to a process for the preparation of the known 4 - amido - 6 - benzoylamino - 1,3-dimethylbenzene, which is to be used for the production of dyes, characterized in that: 6-nitro-1. Reduced 3- dimethylphenyl-4-sulfamic acid, treated the reduction product with benzoyl halide and cleaved the sulfo group by heating with ver dilute mineral acid.

    



  <I> Example: </I> 2! 68 kg of 6-nitro-1,3-dimethylphenyl-4-sulfamic acid sodium (produced by sulfamidation of 6-nitro-4-amido-1,3-dimethylbenzene with chlorosulfonic acid in the presence of a tertiary bastes) are reduced in the usual way at 60 to <B> 70 '</B> with iron and formic acid.

   After the reduction is complete, the solution is made alkaline, the amino compound in solution is pressed from the iron oxide sludge, 145 kg of benzoyl chloride are gradually added to the filtrate at 25 to 30 'with good stirring and kept permanently weakly alkaline with soda.

   When the benzoylation is complete, the mixture is heated to 70 to 80 ', <B> makes the Congo acidic with hydrochloric acid and at the same time increases the temperature to 80 to <B> 9.0'. </B> The saponification is in finished shortly, the hydrochloric acid salt of 4-amino-6-benzoylamido-1,3-dimethylbenzene already falls in the warmth in white. :

  shiny needles and is separated out almost quantitatively by the addition of table salt. It is filtered off with suction, dissolved again in hot water, filtered and the base is precipitated with soda. White needles; Melting point 176, yield 88%, calculated on the nitroarylsulfamic acid used.

 

Claims (1)

PATENT CLAIM: Process for the production of an aromatic monoaroyldiamino compound, characterized in that 6-nitro-1. 3-dimethylphenyl-4-sulfamic acid is reduced, the reduction product is treated with benzoyl halide and the sulfo group is cleaved by heating with dilute mineral acid.