Preparation method of para aminoacet anilide

Abstract

The invention provides a preparation method of para aminoacet anilide. The preparation method comprises the following steps: (1) adding paranitroaniline and glacial acetic acid into a reaction kettle to obtain mixed liquor; (2) heating the mixed liquor obtained in the step (1), and carrying out a heat-preserved distilling reaction in a constant pressure reflux state to obtain reaction liquid; (3) after the reaction liquid obtained in the step (2) is fully dissolved and cooled, filtering, washing and drying to obtain paranitroacetanilide; (4) adding paranitroacetanilide, a catalyst and an organic solvent in a high pressure kettle, and respectively replacing by using nitrogen and hydrogen to obtain para aminoacet anilide solution; (5) filtering the para aminoacet anilide liquor obtained in the step (4) to obtain a para aminoacet anilide coarse product; and (6) adding the para aminoacet anilide coarse product in a solvent, heating for dissolving the para aminoacet anilide coarse product, then cooling, filtering and drying in vacuum to obtain the para aminoacet anilide prodcut. According to the method provided by the invention, existing methods of preparing para aminoacet anilide are changed and the effects of no environmental pollution, high yield and the like in production are achieved.

Description

technical field [0001] The invention relates to industrial dyes, and relates to a preparation method of p-aminoacetanilide. Background technique [0002] P-Aminoacetanilide is a dye intermediate, mainly used to prepare various dyes such as disperse dyes and acid dyes. At present, the methods for preparing p-aminoacetanilide all have deficiencies: the reduction of acetanilide through mixed acid iron nitrate powder under the condition of concentrated sulfuric acid will produce a large amount of acidic waste water in the production, and the environmental pollution is serious. At the same time, the solid produced by the reduction of iron powder Iron mud is more serious to environmental pollution; There is another kind of acylation with acetic anhydride under the condition of glacial acetic acid with p-nitroaniline, obtains the method for p-aminoacetanilide after reduction, this method also produces a large amount of acid waste water during acylation , the environmental pollutio...

AI Technical Summary

Problems solved by technology

At present, the methods for preparing p-aminoacetanilide all have deficiencies: the reduction of acetanilide through mixed acid iron nitrate powder under the condition of concentrated sulfuric acid will produce a large amount of acidic waste water in the production, and the environmental pollution is serious. At the same time, the solid produced by the reduction of iron powder Iron mud is more serious to environmental pollution; There is another kind of acylation with acetic anhydride under the condition of glacial acetic acid with p-nitroaniline, obtains the method for p-aminoacetanilide after reduction, this method also produces a large amount of acid waste water during acylation , the environmental pollution is relatively serious, and acetic anhydride belongs to poisonous chemicals, when the operation or management is improper, it is easy to produce serious adverse consequences; there are also other reported preparation methods whose products have low purity and need to be purified before use, making the preparation The method is complicated and the production cost is high

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