Method for synthesizing 4-nitro diphenylamine and 4-nitroso diphenylamine or/and their salts

Abstract

The invention relates to a method for synthesizing 4-nitrodiphenylamine and 4-nitrosodiphenylamine and / or their salts through continuous condensation reaction using aniline and nitrobenzene as raw materials in the presence of a composite catalyst. That is to choose a cheap composite alkali catalyst, aniline, nitrobenzene and composite alkali catalyst enter the reactor in a certain proportion, and under a certain pressure and temperature, pass through one-stage or multi-stage reactors and forced heat exchangers, using a forced circulation pump The material is partially circulated, dehydrated and reacted at the same time. The invention has mild reaction conditions, few by-products, the conversion rate of nitrobenzene is greater than 99%, and the selectivity is greater than 97%. No corrosive substances are produced, the requirements for equipment are not high, the production is stable, it is easy to realize automatic control, and the production cost is reduced.

Description

technical field [0001] The present invention relates to a kind of synthetic method of organic matter, be specifically related to use aniline and nitrobenzene as raw material, select a kind of compound type base catalyst and technological process, continuously synthesize 4-nitrodiphenylamine and 4-nitrosodiphenylamine and / or or their salt methods. Background technique [0002] At present, the method for synthesizing 4-nitrodiphenylamine and 4-nitrosodiphenylamine and / or their salts is to adopt the nucleophilic aromatic ring substitution hydrogen reaction (NASH), that is, the functionalized carbanion containing a leaving group is The reaction of substituting hydrogen on nitroarenes and aromatic heterocycles in the presence of a strong base. Most compounds are substituted on the ortho position, and the yield is generally between 5-65%. For example, in the presence of tetramethylammonium hydroxide, aniline and nitrobenzene undergo NASH reaction to synthesize 4-nitrodiphenylamin...

AI Technical Summary

Problems solved by technology

Dehydration has a great influence on the parallel reaction of condensation. Generally, strong base catalysts need to be dehydrated in advance, and the requirements for water control are high, that is, the ratio of water to alkali at the beginning of the condensation reaction is required to be not less than 4:1 and not less than 0.6: at the end of the reaction. 1 o'clock (CN1307556A), in the specific embodiment, adopt first dehydration and then enter the reactor to carry out condensation reaction, the operation is complicated, it is difficult to effectively control, and the processing capacity is not large

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