Magnetically retrievable magnetite (Fe3O4) immobilized ionic liquid: an efficient catalyst for the preparation of 1-carbamatoalkyl-2-naphthols

A magnetite (Fe3O4) supported-SO3H functionalized benzimidazolium based ionic liquid has been synthesized via covalent grafting of benzimidazole on a (3-chloropropyl) triethoxysilane functionalized magnetic nanoparticle followed by quaternization reaction with 1,4-butane sultone. The obtained magnetic nanoparticle supported ionic liquid (IL@MNP) has been characterized by FT-IR, TGA, TEM, XRD, VSM, EDX and elemental analysis. The performance of the prepared catalyst was evaluated in the preparation of 1-carbamatoalkyl-2-naphthols. The magnetite supported catalyst showed excellent catalytic activity and the corresponding products were obtained in high yields in all the tested cases. The heterogeneous nature of the magnetite favoured easy recovery and recyclability of the catalyst through magnetic decantation making the protocol highly advantageous over conventional procedures.