Fabrication of a new magnetic zeolite-Y nanocatalyst functionalized with N-methylimidazolium chloride ionic liquid and its application in the three-component and green synthesis of 2-amino-4H-benzo- and naphtho- pyrans

In this research, at first, nanoporous zeolite-NaY was functionalized through reaction with 3-chloropropyltriethoxysilane (organic linker) and then with N-methylimidazole group. Then magnetic nanoparticles (Fe3O4) were formed and stabilized under ultrasonic energy conditions on the surface and internal pores of zeolite-Y (1-MeIm IL@ZY-Fe3O4). The structure of zeolite-ionic liquid prepared as a magnetic nanohybrid using the techniques of FTIR, FESEM, EDS, TGA, BET, XRD and VSM instrumental analyses were identified and confirmed. At the next step, its catalytic performance in the synthesis of a number of 4-aryl-2-amino benzopyran (chromene) or 4-aryl-2-amino naphthopyran (benzochromene) derivatives was investigated through the three-component condensation reaction of aromatic aldehydes, malononitrile and dimedone or β-naphthol, at ambient temperature and aqueous medium. The advantages of this method include the use of cheap, safe and reusable nanocatalyst, easy separation of the heterogeneous catalyst from the reaction medium with the using of a magnet, short reaction time, high yield, easy and fast separation of the product, and the use of non-toxic water solvent, that has made this method in simplicity, be in the scope of "green chemistry".