Preparation method of p-aminophenetole

Abstract

The invention relates to a preparation method of p-aminophenetole, which comprises the following steps: catalytic hydrogenation reaction: in a self-absorption stirred tank reactor, under the reaction conditions of adding ethanol and introducing hydrogen, adding raw materials for mixing reaction; standing and neutralization reaction: after standing, injecting liquid ammonia into the reacted mixed solution, rotating the solution in one direction, monitoring the pH value in real time, and stopping injecting the liquid ammonia when the pH value is 7 + 0.2; carrying out solid-liquid separation: carrying out low-speed stirring type filtration by adopting a high-density filter screen, fully contacting liquid with the screen under the action of rotating flow and the action of vertical gravity and transverse rotating force at the same time, and extracting a solid catalyst of which the particle size is 0.01-0.03 mm or greater than 0.05 mm in the step; liquid-liquid separation: extracting the ethanol; and introducing the mixture into a batch-type rectifying tower, and separating p-aminophenetole and aniline. The method comprehensively improves the extraction and separation of the catalyst and ethanol, and can reduce the production cost and improve the purity of p-phenetidine.

Description

Technical field [0001] The present invention relates to a method for preparing p-aminophenethyl ether. Background [0002] P-Aminophenethyl ether and aniline are important organic intermediates. At present, it is mainly used for the preparation of phenacetin and ethyl vat dyes. In addition, it is also used to prepare azo dyes, ice dyes, etc. P-Aminophenethyl ether and aniline are widely used and have greater demand at home and abroad, so the synthesis of p-aminophenethyl ether and aniline has received more and more attention. [0003] The traditional synthetic routes of p-aminophenethyl ether and aniline mainly include: [0004] (1) Using p-nitrophenol as raw material, ethoxylation reaction with bromoethane under phase transfer catalysis is carried out to generate p-nitrophenethyl ether, and p-amino phenyl ether is generated after reduction reaction; [0005] (2) P-nitrochlorobenzene is used as raw material, and ethanol and sodium hydroxide are used to generate p-nitrophenethyl e...

AI Technical Summary

Problems solved by technology

Usually, p-aminophenethyl ether and aniline are an independent preparation process and separation and refining process. This traditional preparation process has the following disadvantages: high raw material consumption, high salt, large amount of waste water, and the phase transfer catalyst used cannot be recycled, resulting in environmental pollution. , high cost, long production cycle, many unit equipment and unit operations, etc.

[0007] Mr. Zhou Longgen conducted preliminary experiments on related industrial production methods and applied for a patent in 2017. The application number is CN201710351249.0, in which he proposed a method for preparing p-aminophenethyl ether and aniline, and proposed ethanol And the recycling process of solid catalyst, but this method has high requirements for equipment and raw materials in actual production, and in the treatment of solid-liquid separation and liquid-liquid separation, the separation effect needs to be further improved

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