Research On Synthesis Of M-Aminophenol And Separations Of The Products

m-Aminophenol(MAP), an important chemical raw material and organic intermediate, has been widely used for many fields such as, petrochemical industry, agricultural chemicals, pharmacy, and dyestuff. Now so many methods had been discovered to prepare MAP, which included nitrobenzene sulfonated alkali 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hydroxylation of aniline, and m-phenylenediamine hydrolysis with HCl, but those technics have many limitations such as, outdated technics, serious pollution, high costs, high equipment requirement and so on.The paper mainly studied two parts which were the new technics for MAP by m-phenylenediamine hydrolysis with H2SO4 and the separation of hydrolyzate. The contents and results were as follows.The synthetic process of MAP was reviewed, and the optimal reaction conditions were confirmed as follow: the concentration of acid 23%, reaction temperature 190℃, the mole ratio of m-phenylenediamine to acid 1:2.10, reaction time 20 h. Under these conditions the conversion of m-phenylenediamine acid reach up to 99.0%, the yield of MAP was 43.8%and the yield of resorcinol was 54.4%.In addition, the rate equations of m-phenylenediamine hydrolysis at different temperature of 190℃,200℃,and 210℃were also obtained through kinetic experiment and achieved the activation energy and frequency factor of the hydrolysis reaction.In view of process of the preparation of m-aminophenol by hydrolysis of m-phenylenediamine with sulfuric acid contained three components, product of m-aminophenol, resorcinol and a small number of m-phenylenediamine. using butyl acetate to extract resorcinol, and then pure MAP can be accquired by separated the m-phenylenediamine and MAP through crystallization. The crystallization conditions are as follows: the solution pH 7.08, the crystallization temperature15℃, the crystallization time 40 min, stirring speed 500 r·min^-1.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. In addition the product of resorcinol of separation is also an important organic chemical intermediates, so the process is a line of zero emissions of green technology.