Preparation method of N-methyl-p-anisidine

Abstract

The invention discloses a preparation method of N-methyl-p-anisidine. The preparation method comprises the following steps: p-anisidine and methanol as reactants and a composite metal oxide A@B as a catalyst are subjected to a reaction in a fixed bed continuous flow reactor under conditions that reaction temperature is 200-350 DEG C, liquid volume space velocity is 0.1-2.0 h<-1> and N2 is used ascarrier gas, and N-methyl-p-anisidine is obtained; in the composite metal oxide A@B catalyst, A represents the active component CuO-ZnO-NiO or CuO-ZnO-Cr2O3, and B represents one of surface coatings Al2O3, SiO2 and TiO2 or C; the molar ratio of Cu to Zn is 0.1-10:1, the molar ratio of Cu to Ni is 0.1-10:1, and the molar ratio of Cu to Cr is 0.1-10:1; the surface coating Al2O3, SiO2 and TiO2 or C materials account for 1wt%-10wt% of the total amount of the catalyst. The method is simple to operate, and has the advantages of mild conditions, stable catalyst performance, high yield, low cost and low pollution.

Description

technical field [0001] The invention relates to a preparation method of N-methyl-p-methoxyaniline (NMPA). Background technique [0002] From the birth of the automobile industry in the late 19th century to the 21st century, the automobile industry has developed steadily. The production and sales of automobiles have increased year by year. In order to meet the new gasoline specification, it is a key issue to increase the octane number of gasoline, and adding gasoline antiknock agent is an effective means to increase the octane number of gasoline. [0003] Gasoline antiknock agents can be divided into metal ash type and organic ashless type according to their application characteristics. Since the implementation of the National IV gasoline standard on January 1, 2014, my country has entered the era of high standardization and cleanliness. Organic ashless gasoline Anti-knock agent is a new type of gasoline octane booster, which can greatly increase the octane number and realize...

AI Technical Summary

Problems solved by technology

From existing literature reports such as CN 103124717 A, CN 103570553 B, RU2270187, US 8901354, US 5068434, US 5055617, and US 4029707, it is found that the N-monomethyl compound generated in the reaction process is easy to further react with alcohol to form N, N-dimethylated products, this is because the nitrogen atom of N-methyl p-methoxyaniline is more nucleophilic than the nitrogen atom of p-methoxyaniline, so patents with the same or similar structure compounds are more Less; Patent CN 105924363 A adopts p-methoxyaniline and paraformaldehyde as raw materials, and the preparation of N-methyl-p-methoxyaniline by reductive amination method needs problems such as high-pressure hydrogen and the use of non-green solvents. Based on the above reasons, so far So far, there is no mature N-methyl-p-methoxyaniline production process and catalyst at home and abroad, but the research and development of N-methyl-p-methoxyaniline industrial production catalyst and the competition for related production technologies are already very fierce, so the relevant It is imperative to develop and promote industrialization

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