Clean production process for 4-aminoacetanilide

Abstract

The invention discloses a clean production process for 4-aminoacetanilide. Waste sulfuric acid generated during 4-aminoacetanilide production and waste iron sludge generated from a reduction procedureare composited into PFS (polymerized ferrous sulfate). The clean production process includes putting the waste sulfuric acid and the waste iron sludge, both generated by a batch of 4-aminoacetanilide, into a reactor, wherein the molar ratio of iron in the sulfuric acid to iron in the ion sludge is (1.4-1.6):1; increasing the temperature while stirring, and keeping the temperature for two hours toform ferric salt; transferring hot filtrated stock into another reactor, and adding sodium chlorate in batches, wherein the molar ratio of ion in the sodium chlorate to the iron in the iron sludge is0.15:1; directly compositing 4-aminoacetanilide slurry from the reduction procedure into scarlet acid-proof 4BS. The clean production process has the advantages that dangerous waste from 4-aminoacetanilide production is recycled, so that costs of raw materials are reduced, and clean production is achieved; diazotization compounding is conducted directly after reduction of the 4-aminoacetanilide to obtain the scarlet acid-proof 4BS, so that procedures for the 4-aminoacetanilide are simplified, losses are reduced, the yield of the 4-aminoacetanilide can be increased to more than 15%, and energyconservation and emission reduction are realized.

Description

technical field [0001] The invention relates to the technical field of dye intermediate production, in particular to a clean production process of p-aminoacetanilide. Background technique [0002] p-aminoacetanilide, also known as N-acetyl p-phenylenediamine, is an important dye intermediate, mainly used in the preparation of disperse dyes, direct dyes, acid dyes and reactive dyes, such as disperse yellow G, direct acid-resistant scarlet 4BS, acid-resistant products Red 6B, active blue AG, etc. There are currently two methods for industrial production of p-aminoacetanilide. Method 1: Acetanilide is nitrated with mixed acid and then reduced with iron powder. Method 2: p-nitroaniline reacts with acetic anhydride under the action of a catalyst to prepare p-nitroacetanilide, and then reduces it with iron powder. The three wastes in this method are equivalent to the first method, but the raw material acetic anhydride is a precursor drug, and the country has restricted its purc...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a clean production process of p-aminoacetanilide to solve the problem that the p-aminoacetanilide production waste cannot be effectively utilized in the prior art