Azo sulfathiazole-modified UiO-66-NH2 for the three-component synthesis of pyrrolo [1, 2-c] imidazoles

Abstract

In this work, a novel functionalized framework of MOF (UiO-66-AST) has been synthesized by post-synthetic modification (PSM) of UiO-66-NH2. The formation of the UIO-66-AST nanocatalyst was deduced from Thermogravimetric Analysis (TGA), Fourier Transform Infrared spectroscopy (FT-IR), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Micrograph (SEM), Energy Dispersive Spectroscopy (EDS), and Elemental analyses. Then, the catalytic activity of the UIO-66-AST nanocatalyst was investigated for the three-component synthesis of pyrrolo[1,2-c]imidazole derivatives. The results show that the products obtain high to excellent yields (88–97 %) at short reaction times (>1 h) in EtOH/H2O (green solvents). The modification of UIO-66-NH2 has enhanced the catalytic activity which can be due to the increase of dispersibility, and new hydrogen bond formation by OH and SO2NH groups in the modified catalyst (UIO-66-AST). Also, the obtained results show that the catalyst can be recycled and used for up to five subsequent runs without significant loss of activity.