Synthesis and characterization of 4,4′-bipyridinium sulfonic acid chloride as a new and efficient catalyst for the preparation of amidoalkyl phenols and bis amidoalkyl phenols

4,4'-bipyridinium sulfonic acid chloride {[SO3H-4,4'-bipyridine-SO3H]Cl-2}, as a new solid acid, was synthesized and fully characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), H-1 NMR and C-13 NMR as well as mass spectra. [SO3H-4,4'-bipyridine-SO3H]Cl-2 was successfully applied as a new and efficient catalyst for the preparation of amidoalkyl phenols and bis amidoalkyl phenols as a new category of compounds at 110 degrees C under solvent-free conditions. (C) 2017 Elsevier B.V. All rights reserved.