An efficient, one-pot synthesis of 2-amino-4H-chromenes catalyzed by (α-Fe2O3)-MCM-41-supported dual acidic ionic liquid as a novel and recyclable magnetic nanocatalyst

A novel (alpha-Fe2O3)-MCM-41-supported dual acidic ionic liquid (DAIL) catalytic system was prepared. This catalyst was characterized by XRD, TEM, SEM, IR spectra and N-2 adsorption-desorption measurements, TGA and acid-base titration. 1-Methyl-3-(4-sulfobutyl) imidazolium hydrogen sulfate as the DAIL inside the mesochannels of alpha-Fe2O3-MCM-41 led to preparation of a new material which was an efficient magnetic heterogeneous nanocatalyst for one-pot three-component synthesis of some new and known 2-amino-4H-chromenes in water medium conditions. This catalyst was more efficient than other reported catalysts for the synthesis of 2-amino-3-cyano-7-hydroxy-4H-chromenes. High product yields, short reaction times, use of non-corrosives, a robust and reusable magnetic nanocatalyst and water as a green solvent are the most important features of the present work.