Fe3O4@C@PrS-SO3H: A Novel Efficient Magnetically Recoverable Heterogeneous Catalyst in the Ultrasound-Assisted Synthesis of Coumarin Derivatives

A novel magnetic core-shell nano-particles of Fe3O4@C@PrS-SO3H were generated and utilized in the green synthesis of coumarin derivatives under conventional and ultrasound-assisted conditions. The synthesized nano-catalysts were fabricated through a three-step method, including the synthesis of Fe3O4@C nano-particles, then coated by (trimethoxysilyl)-1-propanethiol, finally modified with chlorosulfonic acid. The nano-catalysts were identified using FT-IR, X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TGA) techniques. The catalyst efficiency of the synthesized Fe3O4@C@PrS-SO3H NPs was scrutinized in the Pechmann condensation of phenol and beta-ketoester derivatives under solvent-free conditions. The synthesized catalyst was evaluated as very effective under conventional and ultrasonic assistant reaction conditions. A significant reusable activity was observed for the catalyst. [GRAPHICS] .