Synthesis and Characterization of 1-(Carboxymethyl)Pyridinium Bromide [CMPy]Br Molten Salt: Application as a Novel Nanocatalyst for the Synthesis of Bis-Naphthodipyrans

Abstract

Herein, a convenient method for the synthesis of bis-naphthodipyrans from the condensation of naphthalene-2,3-diol, malononitrile and various aromatic aldehydes using acetic acid functionalized pyridinium salt 1-(carboxymethyl)pyridinium bromide [CMPy]Br as a novel, efficient, reusable and nanocatalyst is described. The synthesized catalyst was fully characterized by using various techniques such as single crystal X-ray diffraction (SCXRD), 1H NMR, 13C NMR, Fourier transform infrared spectroscopy (FT-IR), mass spectra, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and Differential thermal analysis (TG/DTG). The major advantages of the convenient method are high yields, short reaction time, and reusability of the catalyst. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim