Method for preparing 2,6-dichloro-4-nitroaniline through direct chlorination of chlorine gas and oxidative chlorination of hydrogen peroxide

Abstract

The invention relates to a method for preparing 2,6-dichloro-4-nitroaniline through direct chlorination of chlorine gas and oxidative chlorination of hydrogen peroxide. The method comprises the following steps: (1) adding paranitroaniline into hydrochloric acid at the concentration of 5-35wt%, heating to 40-80 DEG C, stirring for uniformly mixing, slowly inflating the chlorine gas within 0.5-5h, slowly adding hydrogen peroxide dropwise, and after adding the chlorine gas and the hydrogen peroxide, continuing to preserve heat and react for 0.3-1.5h; (2) filtering a product obtained in the step (1), washing a filter cake to be neutral, and drying to obtain the 2,6-dichloro-4-nitroaniline. By regulating a dosage ratio of the chlorine gas to the hydrogen peroxide, the concentration of the hydrochloric acid in a reaction system can be kept unchanged, the reaction process is steady and easily controlled, and the product is high in yield and purity.

Description

technical field

[0001] The present invention relates to a preparation method of 2,6-dichloronitro-4-aniline, in particular to a method for simultaneously preparing 2,6-dichloro-4-nitroaniline by direct chlorine chlorination and hydrogen peroxide oxidative chlorination, The invention belongs to the technical field of organic intermediate chemical industry. Background technique

[0002] 2,6-Dichloronitro-4-aniline (alias: 2,6-dichloro-p-nitroaniline; Chloronitroamine), English name: 2,6-Dichloro-4-nitroaniline, molecular formula: C 6 h 4 Cl 2 N 2 o 2 , Molecular weight: 207, Appearance: Yellow needle-like crystal, hardly soluble in water, easily soluble in ethanol and ether, slightly soluble in acetone, chloroform, ethyl acetate, melting point: 186-190°C. 2,6-Dichloronitro-4-aniline is an important dye intermediate, mainly used in the production of disperse dyes such as disperse yellow brown 3GL, disperse yellow brown 2RFL, disperse brown 3R, disperse orange S-4RL, disper...