.2,6 - Dimethylphenol Liquid Phase Catalytic Synthesis Of 2,6 - Dimethyl Aniline Process

The current researching situation of 2,6-dimethylaniline at home and abroad has been reviewed in this paper .The process of synthesizing 2,6-dimethylaniline with 2,6-dimethylphenol and ammonia liquor by liquid phase catalysis is studied .The appropriate catalyst is screened and the effect of process conditions on this reaction is discussed. The mechanism of this reaction is deduced based on the literature and experiments.The mechanism of synthesis of 2,6-dimethylaniline is deduced in this part. First, the process of preparing aniline with phenol and ammonia liquor in the presence of Pd/C is investigated; the process of synthesizing 2,6-dimethylanline in the same conditions is then investigated experimentally. According to the literature and experiments, the mechanism of this reaction is deduced at last.In the part of catalyst's evaluation, several catalysts are compared, and then the content of Pd of catalyst and the diameter of charcoal is discussed. As a result , 5 %(wt)Pd/C is recommend, the proper average diameter of charcoal is about 28 to34μm .In the part of optimizing process conditions ,the effects of reaction time ,reaction temperature ,reaction pressure and the dosage of Pd/C is discussed respectively .As a result ,this method does not use solvent ,the reaction conditions recommended are as follows : in the hydrogenolysis of 2,6-dimethylphenol : reaction time is about 15 to 25 min, reaction temperature is 150 to 200℃ ,hydrogen pressure is 4.0MPa; then add ammonia liquor, reaction time is 8 to10h, reaction temperature is 250℃, hydrogen pressure is 2.0MPa, raw material ratio is n(2,6-dimethylphenol): n(ammonia liquor)=1:3(mol), the dosage of Pd/C(5%wt) is 5 %.In addition, the process condition of synthesizing 2,6-dimethylaniline is applied to synthesize 3,5-dimethylaniline, ortho-toluidine and aniline .It is proved that this method can be applied to synthesize some aromatic compound with corresponding aromatic hydroxyl compound and ammonia liquor in the presence of Pd/C.In brief, the synthesis of 2,6-dimethylaniline with 2,6-dimethylphenol and ammonia liquor by liquid phase catalysis is studied systematically in this paper .All of this proved theoretically foundation and scientific basis for industrialization. Wang Wanqin (Fine Chemical engineering)Directed by adjunct professor Zhang Xiucheng...