Parachloroaniline production method without using anti-dechlorination agent

Abstract

The invention discloses a parachloroaniline production method without using an anti-dechlorination agent. The production method is characterized by comprising the following steps: adding para-nitrochlorobenzene and a catalyst in an autoclave; performing sealing; opening a hydrogen gas valve, introducing hydrogen gas into the autoclave and simultaneously performing stirring, heating and pressurization, wherein the reacting rotation speed is set to 700 rpm, the reacting temperature is controlled to 110-120 DEG C and the reaction pressure is controlled to 1.1-1.2 Mpa; allowing reaction to last until hydrogen absorption is stopped; closing the hydrogen gas valve; performing cooling, and opening the autoclave; discharging; filtering, and rectifying in a rectifying still, thereby obtaining parachloroaniline. According to a gas chromatographic analysis result of sampling, the purity of parachloroaniline is 99.85% and the dechlorination degree is 0.006%. Since no extra anti-dechlorination agent is added, a best anti-dechlorination effect is achieved. The production method is simple to operate and short in production cycle and has little pollution to environment; since by-products are reduced, the yield of products is enhanced effectively. With a cost reduction and a benefit increase, the production method is suitable to industrial production.

Description

1. Technical field: [0001] The invention relates to a method for producing p-chloroaniline, in particular to a method for producing p-chloroaniline without using an anti-dechlorination agent. 2. Background technology: [0002] p-Chloroaniline is an important fine chemical intermediate, which is widely used in the production of fine chemicals such as pesticides, dyes, medicines, spices and rubber additives. The traditional production methods of p-chloroaniline mainly include iron powder reduction method, alkali sulfide reduction method, electrochemical reduction method, and catalytic hydrogenation reduction method. The iron powder reduction method produces a large amount of iron sludge, which seriously pollutes the environment, and the product purity is not high; the alkali sulfide reduction method has the disadvantages of complex reduction route, low product yield, and large amount of waste liquid; the electrochemical reduction method consumes too much energy; The hydrogena...

AI Technical Summary

Problems solved by technology

However, the use of anti-dechlorination agent will increase the product separation operation, which will cause a series of problems such as increased investment cost, increased energy consumption, reduced safety factor, and worsened working environment.