Preparation method of 3-acetamido-N,N-diacetoxyethylaniline

Abstract

The invention discloses a preparation method of a dye intermediate that is 3-acetamido-N,N-dimethylformamide. The method comprises the following steps: adding a mechanically applied mother solution and m-aminoacetanilide hydrochloride into a neutralization reaction kettle, heating, neutralizing with a sodium hydroxide solution to the reaction endpoint, and carrying out liquid-liquid sedimentationlayering within the temperature range after heating; separating lower-layer salt and mother liquor, performing filtration to remove the salt while the mother liquor is hot, and applying the obtained mother liquor in the next batch; carrying out nitrogen displacement on the upper-layer oil phase, heating the material, and dropwise adding ethylene oxide to carry out a hydroxyethylation reaction; andafter the hydroxyethylation reaction is finished, transferring the material to an esterification kettle, heating, then dropwise adding acetic anhydride to carry out an esterification reaction, and cooling to 35 DEG C after the reaction is finished, thereby obtaining an acetic acid solution of 3-acetamido-N,N-diacetoxyethylaniline. The method is simple in technological process, easy to operate andcontrol, low in wastewater generation, and low in energy consumption and material consumption. A dehydration process before esterification is omitted, so that the production machine-hour is greatly shortened.

Description

technical field [0001] The invention belongs to the field of preparation of organic chemical intermediate products, and in particular relates to a preparation method of a dye intermediate 3-acetylamino-N,N-diacetoxyethylaniline. Background technique [0002] 3-Acetamido-N,N-diacetoxyethylaniline, commonly known as ruby ​​esterification solution, is a very important coupling component intermediate in disperse dyes. It is mainly used in the intermediates of synthetic dyes Disperse Red 167 and Disperse Red 74, etc. [0003] The traditional 3-acetamido-N,N-diacetoxyethylaniline production method comprises the following steps: [0004] 1. Neutralization - use m-aminoacetanilide hydrochloride as raw material, water as medium, neutralize with sodium hydroxide solution; 2. Hydroxyethylation - add ethylene oxide to the obtained reaction product for hydroxyethylation Reaction; 3. Negative pressure distillation and dehydration—the hydroxyethylated product is subjected to negative pre...

AI Technical Summary

Problems solved by technology

[0006] First, the neutralization reaction mixture contains a large amount of water, which will cause partial hydrolysis of ethylene oxide during the hydroxyethylation reaction and increase the consumption of raw materials;

[0007] Second, the negative pressure distillation dehydration process takes a long time and consumes a lot of energy;

[0008] Third, after desalination by filtration, some products and by-product acetic acid adhere to the surface of the salt, which affects the total yield of the product, increases the difficulty of solid waste treatment, and has a strong smell of acetic acid during the operation

Images