HClO4-functionalized silica-coated magnetic nanoparticles [gamma-Fe2O3@SiO2-HClO4] (2.5 mol%) has been found to be a capable biocompatible and recyclable catalyst for highly efficient conversion of a variety of alcohols to corresponding amides via modified Ritter reaction in good to excellent yields. Since this heterogeneous catalyst can be simply removed by using an external magnetic device then recovered, it also enhances product purity and promises economic. (C) 2010 Elsevier B.V. All rights reserved.