Method and catalyst for carrying out selective nitro reduction hydrogenation reaction by using micro-packed bed

Abstract

The invention discloses a method for carrying out selective nitro reduction hydrogenation reaction by using a micro-packed bed and a catalyst. Comprising the following steps: (1) mixing a reaction substrate with a reaction solvent to prepare a raw material solution; (2) introducing the raw material liquid and hydrogen into a microreactor for reaction, wherein a reaction tube of the microreactor is filled with a modified catalyst; the modified catalyst comprises a catalyst active component, a catalyst auxiliary agent and a catalyst carrier; the catalyst active component is selected from one or more of Pd, Ru and Pt; the catalyst auxiliary agent is selected from one or more of Fe, Cu, Ni and Co; the catalyst carrier is activated carbon; and (3) carrying out gas-liquid separation and purification on a gas-liquid mixture obtained after the reaction is finished to obtain a reaction product. Through the combination of the micropacked bed and the modified catalyst, nitro reduction is realized with high selectivity, the selectivity can reach 99%, and the generation of by-products is effectively reduced.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method and a catalyst for a selective nitro reduction hydrogenation reaction using a micro-packed bed. Background technique [0002] Amines widely exist in the biological world and have extremely important physiological and biological activities. For example, proteins, nucleic acids, many hormones, antibiotics and alkaloids are all derivatives of amines. Most of the drugs used clinically are also amines or amines. derivative. Among them, most of the amine derivatives such as pharmaceutical intermediates and APIs often need to introduce halogens and unsaturated double bonds to prepare drug molecules with different activities. Therefore, in the process of drug synthesis, how to solve the problem of reducing the nitro group in the substrate to an amine group while preventing the reduction of halogen and unsaturated double bonds has very important commercial value. [0003] At pr...

AI Technical Summary

Problems solved by technology

However, the preparation process of nano-Pt catalysts is complex and expensive, which is not conducive to industrial production; Raney-Ni metal skeleton catalysts are poor in stability, flammable and explosive, and are prone to safety hazards; Pd / C catalysts are prone to dehalogenation impurities, and the selectivity is not high. ; The Ru / C catalyst has a poor effect on nitro group reduction, and is prone to produce double bond hydrogenation impurities

[0004] For the traditional nitro reduction reaction, batch reactors equipped with stirring paddles are generally selected as reactors. Although stirring can enhance the efficiency of gas-liquid mass transfer and heat transfer, there are still disadvantages such as low mass transfer efficiency, long reaction time, and poor selectivity.

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