Synthetic method for halogenated aniline

Abstract

The invention provides a synthetic method for halogenated aniline. The method comprises the following steps that a carbon-coated nickel nanocomposite serves as a catalyst, and halogenated nitrobenzeneis catalyzed to be subjected to hydrogenation reduction reaction in a hydrogen atmosphere, wherein the nanocomposite contains a core-shell structure with a shell layer and a core, the shell layer isa graphitized carbon layer doped with nitrogen and oxygen, the core is nickel nano-particles, and the nanocomposite is a mesoporous material with at least one mesopore distribution peak. According tothe method, the carbon-coated nickel nanocomposite is adopted as the catalyst, the rich mesoporous structure facilitates the mass transfer of the catalytic reaction, the nanocomposite is tightly coated with the metal nano-particles, so that the effect can be conveniently achieved under a more severe condition, the method is used for synthesizing the halogenated aniline through the hydrogenation reduction of the halogenated nitrobenzene, excellent activity, selectivity and safety are achieved, and the dehalogenation problem in the reaction process can be effectively ameliorated.

Description

technical field [0001] The invention belongs to the field of catalysis, and in particular relates to a synthesis method of halogenated aniline. Background technique [0002] Halogenated aniline is an important organic chemical intermediate, which is widely used in the synthesis of fine chemicals such as medicine, pesticide, fuel, etc. It is usually prepared by reduction synthesis of halogenated aromatic compounds. The reduction methods of halogenated aromatic compounds include chemical reduction methods such as alkali sulfide reduction method, iron powder reduction method, hydrazine hydrate reduction method, electrolytic reduction method, and catalytic hydrogenation reduction method. Although the chemical reduction method has a simple process route and is relatively mature in technology, this method generally has defects such as large environmental pollution, low product yield, poor product quality and high energy consumption, and it is showing a tendency to be eliminated. ...

AI Technical Summary

Problems solved by technology

Pt and Pd noble metal catalysts have the advantages of high catalytic activity and mild reaction conditions, but the price and cost of noble metal catalysts are too high, and the loss of noble metals is harmful to the environment, so their application in industrial production is limited.

Non-precious metal catalysts, such as nickel, also have a series of problems in actual production and application, for example, they are prone to agglomeration during the preparation process, easy to be eluted during the catalytic hydrogenation process, poor stability, and greater safety hazards, etc.

In addition, whether it is a noble metal catalyst or a non-noble metal catalyst, the problem of dehalogenation of halonitrobenzene is common in the process of catalytic hydrogenation of p-halogenated nitrobenzene, which reduces the yield and quality of the product, and the dehalogenation reaction produces Hydrohalic acid will corrode equipment, so the key technology for preparing haloaniline by catalytic hydrogenation reduction method when suppressing dehalogenation side reactions

Images