Fe ₃ O ₄ @Sal-cu as a highly efficient magnetic nano-catalyst for the synthesis of 2-substituted benzimidazoles under ultrasonic irradiation and solvent free condition

Fe3O4@propyl-semicarbazide-salicyl aldehyde-Cu (Fe3O4@sal-Cu) nanocatalyst was synthesized and characterized by several methods including XRD, SEM, EDX, VSM and FT-IR analyses. The Fe3O4@sal-Cu has been used as an efficient recyclable magnetic catalyst for the preparation of benzimidazoles. The catalyst was conveniently separated from the reaction mixture by an external magnet, and could be reused without any considerable change in catalytic activity.