Research On The Synthesis Process Of P-aminoanisole

P-aminoanisole is an important dye and pharmaceutical intermediate,which can be used in the production of ice-dye dyes,reducing dyes,disperse dyes,reactive dyes and a variety of color phenols.In the production of pharmaceuticals,it can be used in the synthesis of a variety of drugs such as atipine,anti-inflammatory pain,etc.With the rapid development of China’s chemical industry in recent years,especially the introduction of new medicines in the pharmaceutic field,leading to the increasing demand for p-aminoanisole,and the development prospect is very broad.In this study,p-chloronitrobenzene was used as raw material to prepare paminoanisole by methoxylation and hydrogenation reduction process.This method has less ‘ three wastes ’ emission and less environmental pollution,which is a relatively green production process.We used homemade sodium methanol to participate in the reaction.The effect of each reaction condition on product selectivity and yield was investigated.The optimal experimental conditions were determined as follows: sodium methanol∶p-chloronitrobenzene∶methanol（molar ratio）= 1.1∶1∶8,reaction temperature 110℃,reaction time 4 hours,and the stirring rate was 300 r/min.The purity of p-nitroanisole obtained after filtration,washing and drying of the reaction product was above 99.25%.For the by-product of this reaction,p-nitrophenol was recycled by extraction,waste liquid was treated with porous carbon adsorption,The yield of the whole methoxylation reaction was above 96.32%.In the second hydrogenation reduction step,a series of modified skeleton nickel catalysts were prepared by using Ni,Al,Mo,Ti and Cr powders.By testing the catalytic activity of different catalysts,it was determined that the Ni-Al-Mo modified skeletal nickel catalysts had better catalytic activity and stability for this reaction.The optimal hydrogenation reduction conditions were determined as follows: the reaction temperature 100℃,the hydrogenation pressure was 1.5 MPa,the reaction time 2 hours,the reaction solvent was methanol,and the optimal catalyst dosage 5%.The catalytic activity of the catalyst remains high after several cycles.After multiple reactions,the catalysts were washed with different solvents and sonicated.We found that the catalyst activity was higher after sonication by methanol washing.After hydrogenation,the reaction solution was distilled to obtain pure p-aminoanisole,the product purity of the product was 99.51%.The product yield of the whole hydrogenation process is 97.16%.