Efficient one-pot synthesis of 4-hydroxy-2H chromene by heterogeneously catalyzed ZnO NP and mesoporous aluminosilicate catalysts in solvent free condition

Abstract

4-Hydroxy-2H chromenes are fused benzopyran rings, an important class of biologically active compounds that are widely used as antibacterial, antiviral, antitumor, and anticancer agents. In this paper, we report the synthesis of 4-hydroxy-2H chromenes using two catalysts: (i) ZnO nanoparticles and (ii) mesoporous ZnO/AlSBA-15(7). The ZnO nanoparticle catalyst was prepared using leaf extract, and ZnO/AlSBA-15(7) catalysts were prepared by a wet chemical route. All catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, and N2 sorption techniques. The catalytic activity of the synthesized catalyst was evaluated in a one-pot reaction using aromatic aldehyde and coumarin and was found to have a maximum yield of 81% at 80 °C, with a catalyst dose of 10 mmol %, and in a time limit of 4 h.