Direct Hydrolysis Of Preparation Of Toluidine A Phenol Technology Research

M-cresol is an important intermediate in the organic synthesis.In this paper we reported a new route.It is the Preparation of m-cresol from direct hydrolysis of m-toluidine.The reaction step is only one.This route consist several parts.Firstly,Charging m-toluidine and acid in an aqueous solution to a reactor vessel made of zirconium.secondly,Sealing said vessel and replace air with N₂,heating said aqueous solution in said reactor vesser some time in different temperature.Finally,cooling said aqueous solution and extracting m-cresol from said aqueous solution with an organic solvent.Optimizing the synthetical technic by the means of orthogonal or single factor analysis. As can be seen from the results,H₃PO₄ is the best catalyzer,which is compared with HCl,H₂SO₄ and HZSM-5.Also can gain the satisfying reaction result in the temperature of 270～285℃,reactiontime of 12～24h,n(H₃PO₄)/n(m-toluidine)=2.3～3.0, n(H₂O)/n(m-toluidine)=20～35.In the best reaction condition temperature of 280℃,reaction time of 14h,n(H₃PO₄)/n(m-toluidine)= 2.5,n(H₂O)/n(m-toluidine)=30,The average yield of m-cresol can get 83.58%.In addition,This paper Study the reaction in series and get some good result,Also present a process technology map,Which is benefit of industrialization.The author studied the mechanism of the hydrolysis of m-toluidine elementary as well. Through experiments author found that the reaction is in acid conditions,the first formation of ammonium amine substances,water re-hydroxy this attack and to replace ammonium salt and a final product of m-cresol.