Synthesis method of halogenated aniline

Abstract

The invention provides a synthesis method of halogenated aniline. The synthesis method comprises the following steps: taking a carbon-coated nickel nano composite material containing alkali metals asa catalyst, and catalyzing a hydrogenation reduction reaction of halogenated nitrobenzene in a hydrogen atmosphere; wherein the nano composite material contains a core-shell structure with a shell layer and an inner core, the shell layer is a graphitized carbon layer containing alkali metals, nitrogen and oxygen, and the inner core is nickel nano particles. According to the method, the nano composite material is used as a catalyst; a carbon material and the nickel nano particles generate a synergistic effect and a good catalytic effect, the alkali metals of the shell layer further synergistically improve the catalytic performance of the nano composite material, and the catalyst is used for hydrogenation reduction of halogenated nitrobenzene to synthesize halogenated aniline, has excellentactivity, selectivity and safety, and can effectively solve the dehalogenation problem in the reaction process.

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. ...

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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

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