SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2013, Vol. 21 ›› Issue (6): 701-704.DOI: 10.1016/S1004-9541(13)60499-X

• 研究简报 • 上一篇    

Synthesis of 2-Methyl-4-methoxyaniline from o-Nitrotoluene Using Pt/C and Acidic Ionic Liquid as Catalyst System

刘迎新, 李喜英, 方艳艳, 张琳   

  1. Research and Development Base of Catalytic Hydrogenation, College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
  • 收稿日期:2012-03-21 修回日期:2012-11-03 出版日期:2013-06-28 发布日期:2013-07-03
  • 通讯作者: LIU Yingxin
  • 基金资助:

    Supported by the National Natural Science Foundation of China (21106134) and the Natural Science Foundation of Zhejiang Province (Y4100671).

Synthesis of 2-Methyl-4-methoxyaniline from o-Nitrotoluene Using Pt/C and Acidic Ionic Liquid as Catalyst System

LIU Yingxin, LI Xiying, FANG Yanyan, ZHANG Lin   

  1. Research and Development Base of Catalytic Hydrogenation, College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310032, China
  • Received:2012-03-21 Revised:2012-11-03 Online:2013-06-28 Published:2013-07-03
  • Contact: LIU Yingxin
  • Supported by:

    Supported by the National Natural Science Foundation of China (21106134) and the Natural Science Foundation of Zhejiang Province (Y4100671).

摘要: 2-Methyl-4-methoxyaniline (MMA) was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-(propyl-3-sulfonate)-3-methylimidazolium hydrosulfate ([HSO3-pmim][HSO4]) as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.

关键词: acidic ionic liquid, Bamberger rearrangement, 2-methyl-4-methoxyaniline, o-nitrotoluene, hydrogenation

Abstract: 2-Methyl-4-methoxyaniline (MMA) was synthesized by one-pot method through the hydrogenation and Bamberger rearrangement of o-nitrotoluene in methanol using acidic ionic liquid and 3% Pt/C as catalyst system. The effects of ionic liquid type, dosage of ionic liquid and 3% Pt/C, reaction temperature and reaction pressure on o-nitrotoluene conversion and MMA selectivity were investigated. The results indicated that the imidazolium-based acidic ionic liquid which contains SO3H-functionalized cation showed higher selectivity to MMA than other acidic ionic liquids used in this work. Using 1-(propyl-3-sulfonate)-3-methylimidazolium hydrosulfate ([HSO3-pmim][HSO4]) as the acid catalyst, the selectivity to MMA was as high as 67.6% at 97.8% of o-nitrotoluene conversion. As 3% Pt/C increased from 0.01 g to 0.025 g, the selectivity to MMA decreased from 73.4% to 62.5%, because of the hydrogenation of intermediate o-methyl-phenylhydroxylamine to o-toluidine becoming more dominant. An increase in hydrogen pressure also had obviously dramatic effect in lowering the MMA selectivity. After easy separation from the products, the catalyst system could be reused at least 3 times.

Key words: acidic ionic liquid, Bamberger rearrangement, 2-methyl-4-methoxyaniline, o-nitrotoluene, hydrogenation