Research On Synthesis Of M-Aminophenol By Hydrolysis Of M-Phenylenediamine

m-Aminophenol(MAP),an important chemical raw material and organic intermediate,has been widely used for many fields such as,petrochemical industry,agricultural chemicals, dyestuff, and pharmacy. Now so many solutions had been found to prepare MAP, which included nitrobenzene sulfonated akkali fusion, resorcinol liquid ammonolysis solution, m-nitrophenol electrolysis,hydroxylation of aniline,and m-phenylenediamine hydrolysis with HCl,but those technics have many limitations such as,outdated technics,serious pollution, high costs,low yield and selectivity, high equipment requirement and so on.So this technics for MAP by m-phenylenediamine hydrolysis with H2SO4 was reported and systematically studied in this paper. The separation of hydrolyzate and the hydrolysis of m-phenylenediamine were two points the article focus on, and the results were reported as follow.The extraction for separating MAP, m-aminophenol and resorcinol was researched, and the results showed that the better extractant were isopentyl acetate and BuAc, and the optimal operation condition was also detetmined.The liquid-liquid equilibrium of MAP, or m-phenylenediamine, or resorcinol with different solvent as extraction were studied,respectively, and the results showed that BuAc was better than isopentyl acetate for the separation. The equilibrium data were related with Hand equation, and the pratical formulas of the system resorcinol, the system m-phenylenediamine, and the system MAP with BuAc as extractant were found out.The synthetic process of MAP was explored, and the optimal reaction conditions were confirmed as follow: the concentration of acid 22%, reaction temperature 200℃, the mole ratio of m-phenylenediamine to acid 1:1.98, reaction time 6 h. Under these conditions the conversion of m-phenylenediamine acid can reach up to 81.19%, and the yield and selectivity of MAP was 56.34% and 69.38%, respectively, and the yield of by-product resorcinol was 24.13%.In addition, the rate equations of m-phenylenediamine hydrolysis at different temperature of 190℃,200℃,and 210℃were also obtained through kinetic experiment, which can give the actual operation theoretical guidance.In this acticle, the new technics for MAP by m-phenylenediamine hydrolysis with H2SO4 was recored, the separation of hydrolyzate with the method of solvent extraction was studied, the reaction condition was optimized,and rate equation under different temperature was obtained. Those results had not been reported with any literature, and lay foundation for the in-depth research on this process.