Process for the preparation of pure, aromatic o-hydroxy-carboxylic acid aryl amides
AssigneeHoechst Aktiengesellschaft
InventorsSighart Miedtank, Adam Ruffer, Hans Galster
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Abstract
Process for the preparation of pure aromatic o-hydroxy-carboxylic acid aryl amides by condensing an aromatic o-hydroxy-carboxylic acid with an aryl amine in the presence of phosphorus chlorides in an organic solvent or diluent, which process comprises treating the reaction mixture or the reaction product with 1 to 25 %, calculated on the weight of the reaction product, of an aliphatic amino-polycarboxylic acid as chelate forming agent. It is not necessary to purify the products, because they are obtained in such a pure form that they can be used directly as coupling components for azo pigments.
Claims10
In a process for the preparation of an aromatic o-hydroxy-carboxylic acid aryl amide by condensing an aromatic o-hydroxy-carboxylic acid with an aryl amine in the presence of phosphorus chlorides in an organic solvent or diluent, the improvement comprising adding to the reaction mixture or the reaction product 1 to 25 %, calculated on the weight of the reaction product, of an aliphatic aminopolycarboxylic acid or an alkali metal or alkaline earth metal salt thereof as chelate forming agent.
Dependencies are inferred from the claim text.