Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (2): 422-428.doi: 10.3866/PKU.WHXB201512082

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Kinetics of Acid-Catalyzed Smiles Rearrangement of 2, 6-Dimethoxy-2-pyrimidinyloxy-N-arylbenzylamine Derivatives

Pei-Zhi ZHANG1,2,*(),Mei-Jun YE3,Wei-Lian HU1,Jun WU4,*()   

  1. 1 School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, P. R. China
    2 Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, P. R. China
    3 Hangzhou Tea Research Institute, China COOP, Hangzhou 310016, P. R. China
    4 Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China
  • Received:2015-08-24 Published:2016-01-30
  • Contact: Pei-Zhi ZHANG,Jun WU;
  • Supported by:
    the National Natural Science Foundation of China(31471807);Special Fund for Agro-scientific Research in thePublic Interest, China(201403030)


The kinetics of the acid-catalyzed Smiles rearrangement reactions of 2, 6-dimethoxy-2-pyrimidinyloxy-N-arylbenzylamine derivatives was investigated. The effects of initial concentrations of hydrochloric acid, solvent, temperature, and substituent on reaction rates were examined. The results show that the rates increase with an increase in the initial concentration of hydrochloric acid. The reactivity order is CH3OH > C2H5OH > CH3SOCH3 > CH3CN in a single solvent, but rates markedly increase in mixed CH3OH/H2O (1:1, V/V) and the apparent reaction rate constant (kobs) is 5.27 times that of methanol. The rates for the derivatives are found to increase with an increase in temperature at 25-45 ℃, and no significant differences in activation energy (73.99-76.92 kJ·mol-1), activation enthalpy (71.57-74.38 kJ·mol-1), and Gibbs free energy (81.51-85.77 kJ·mol-1) are observed between them, except that there is difference in activation entropy (-24.38 --47.11 J·K-1·mol-1). There is a good linear relationship between substituents and the apparent reaction rate constants, and it is speculated that electron-withdrawing groups in the benzene ring will increase the reaction rates. A relevant reaction mechanism is suggested.

Key words: Kinetics, Reaction mechanism, 2, 6-Dimethoxy-2-pyrimidinyloxy-N-arylbenzylamine derivatives, Smiles rearrangement, Acid-catalyzed reaction