Poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate: An efficient, heterogeneous poly(ionic liquid), solid acid catalyst for the one-pot preparation of 1-amidoalkyl-2-naphthols and substituted quinolines under solvent-free conditions

Abstract

Poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate has been used as an efficient dual acidic catalyst for the one-pot preparation of 1-amidoalkyl-2-naphthols and substituted quinolines under solvent-free conditions. The catalyst was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermo-gravimetric analysis. The results revealed several advantages to our new catalyst system, including its reusability, facile work-up procedure, eco-friendly reaction conditions, short reaction time, and high product yields. The application of poly(ionic liquids) (PILs) as novel catalysts provides chemists with the advantages of ionic liquids (ILs) as well as those of heterogeneous catalysts. Poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate has been used as dual acidic PIL for the one-pot multi-component syntheses of 1-amidoalkyl-2-naphthols and substituted quinolones.