Method for producing 2,5-dichloroaniline without anti-dechlorinating agent

Abstract

The invention provides a method for producing 2,5-dichloroaniline without an anti-dechlorinating agent. The method is characterized by comprising the following steps of: adding 2,5-dichloronitrobenzene and a catalyst into a high-pressure kettle, sealing, opening a hydrogen valve, and introducing hydrogen into the high-pressure kettle; stirring, heating and pressurizing, setting the reaction rotating speed to be 700 revolutions / minute, controlling the reaction temperature to be 110-120 DEG C and the reaction pressure to be 1.1-1.2MPa, and reacting until hydrogen cannot be absorbed; closing the hydrogen valve, cooling, opening the high-pressure kettle, and discharging; filtering, adding into a rectifying still for distillation to obtain 2,5-dichloroaniline after the distillation is finished. A sample is collected, and gas chromatography results indicate that the purity of 2,5-dichloroaniline is 99.85 percent, and dechlorination rate is 0.006 percent. The anti-dechlorinating agent is not needed to be extra added, so that the best anti-dechlorination effect can be achieved. The method is easy to operate, short in production cycle and small in environmental pollution, and can reduce generation of side products, so that the product yield can be effectively increased, cost can be reduced, and benefit can be increased. Therefore, the method is suitable for industrial production.

Description

1. Technical field: [0001] The invention relates to a method for producing p-chloroaniline, in particular to a method for producing 2,5-dichloroaniline without using an anti-dechlorination agent. 2. Background technology: [0002] 2,5-Dichloroaniline is an important fine chemical intermediate, which is widely used in the production of fine chemicals such as dyes, medicines, spices and rubber additives. The traditional production methods of 2,5-dichloroaniline 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.