Preparation of HC1 modified pyridinium aluminum chloride ionic liquids and its catalytic performance in highly selective synthesis of 2,6-dimethylnaphthanlene

摘要

Pyridinium aluminum chloride ionic liquid (PyHClAlCl3) was prepared and modified by HC1. The PyHClAlCl3 and the HC1-modified ionic liquid Py-HCl-AlCl3HCl were characterized by pyridine adsorbed FT-IR spectra (Py-IR), UV-visible spectra and 27A1 NMR measurements, respectively. In PyHCl-AlCl3 and PyHClAlCl3-HCl, the transalkylation of 2methylnaphthanlene (2-MN) with 1,2,4,5tetramethylbenzene (TeMB) for the highly selective synthesis of 2,6-dimethylnaphthalene (2,6-DMN) was performed. The influences of the reaction temperature and the HCl-modification on the transalkylation were investigated. Under the optimal reaction conditions, 14.8% of the 2-MN conversion was reached with 100% of 2,6-DMN selectivity by using the PyHCl-AlCl3-HCl as a catalyst.