Fe3O4 magnetic nanoparticles (MNPs) as an effective catalyst for synthesis of indole derivatives

The principal aim of this research is the application of Fe3O4 (MNPs) in the synthesis of some indole derivatives. Fe3O4 MNPs were prepared by Co-Precipitation method from the reaction of FeCl2.4H2O and FeCl3.6H2O in ammonia solution. Morphology and structure of Fe3O4 MNPs were determined by FT-IR, X-Ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Fe3O4 (MNPs) has been used as a highly efficient catalyst for the synthesis of some Indole derivatives like 6H-Indole [2,3-b] quinoxaline, 3-methyl–6H-Indole [2,3-b] quinoxaline and (z)-3-(pyridine-2-yl-imino)-Indole-2-one. The reaction was carried out using various amounts of Fe3O4 nanoparticles in various solvents and solvent-free conditions. The optimum amount of nano-Fe3O4 was 5 mol% in THF under reflux conditions. The structures of indole derivatives were further established by NMR, and FT-IR spectra. In view of excellent catalytic capacity, the exceedingly simple workup procedure, environmentally friendly reaction and good yield, Fe3O4 (MNPs) was proved to be the good catalyst for this reaction.