Method for preparing p-anisidine through catalytic hydrogenation of p-nitroanisole

Abstract

The invention discloses a method for preparing p-anisidine through catalytic hydrogenation of p-nitroanisole. According to the method, p-nitroanisole is used as a reaction raw material and subjected to a reaction in an enclosed reactor with a mechanical stirring function under the conditions of usage of a composite catalyst, no usage of a solvent, a reaction temperature of 80 to 150 DEG C and hydrogen pressure of 0.3 to 1 MPa so as to obtain p-anisidine, wherein the composite catalyst is composed of active components metal M and a carrier; the active components metal M are composed of two or more selected from a group consisting of Cu, Ni, Fe, Zn, Co, Cr and Mo, and the content of the active components metal M accounts for 0.3 to 25 wt% of the mass of the composite catalyst; and the carrier is prepared by compounding a carbon-containing organic matter and an inorganic oxide, a mass ratio of the carbon-containing organic matter to the inorganic oxide is 1: 50 to 1: 10, and the inorganicoxide is any one selected from a group consisting of SiO2, Al2O3, MgO, TiO2, CeO2 and a 4A molecular sieve. The composite catalyst used in the invention has high catalytic activity, stable performance and high selectivity and conversion rate.

Description

technical field [0001] The invention relates to a method for preparing p-aminoanisole by heterogeneous catalytic hydrogenation of p-nitroanisole. Background technique [0002] P-aminoanisole, also known as p-methoxyaniline or p-anisidine, is a traditional fine chemical widely used in pharmaceutical intermediates, photographic materials, agricultural chemicals, polymers, dyes and other fields. According to incomplete statistics, my country is the main producer and supplier of p-aminoanisole in the world, and the output of p-aminoanisole accounts for about 80% of the global output. At present, the traditional industrial production method of producing p-aminoanisole through p-nitroanisole in China is to adopt the soda sulfide method or the iron powder reduction method. However, the above two methods have many problems such as high energy consumption, high input cost, low conversion rate and selectivity, a large amount of waste residue, and serious environmental pollution by wa...

AI Technical Summary

Problems solved by technology

The performance of the catalyst is excellent, and the yield of the product reaches 99%, but the catalyst is mainly composed of noble metal ruthenium, and the production cost is high; meanwhile, the preparation process of the catalyst is complicated, requires high equipment, and requires a large investment, making it difficult for industrial application

[0006] Throughout the above various reports, the prior art has not been able to realize the method for preparing p-aminoanisole with high selectivity and high yield on the scale of industrial production so far.

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