Novel ionic liquid [Et3N-SO3H][MeSO3]: Synthesis, characterization and catalytic performance for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes

Abstract

The main aim of this work is introducing a novel protic acidic ionic-liquid catalyst for organic synthesis. Thus, N,N-diethyl-N-sulfoethanaminium methanesulfonate ([Et3N-SO3H][MeSO3]) was synthesized by the reaction of triethylamine with chlorosulfonic acid, and then with methanesulfonic acid. The structure of this novel protic acidic ionic liquid was identified by FT-IR, 1 H NMR, 13 C NMR and mass spectral data. Its catalytic activity was examined for the solvent-free reaction of 2-naphthol with arylaldehydes to provide 14-aryl-14Hdibenzo[a,j]xanthenes. [Et3N-SO3H][MeSO3] efficiently catalyzed the reaction, and the products were obtained in high to excellent yields and in short reaction times.