Efficient, one-pot synthesis of xanthene derivatives using Fe3O4@SiO2-Propyl-Pip-SO3H.HSO4 as a magnetically recyclable catalyst under solvent-free conditions

An efficient and green method has been introduced for the synthesis of xanthene derivatives through a one-pot condensation of aldehydes and dimedone in the presence of Fe3O4@SiO2-Propyl-Pip-SO3H.HSO4 as a magnetically recyclable catalyst under solvent-free conditions with excellent yields. The catalyst is easily prepared and characterized using various techniques such as Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), Thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDX) and Scanning electron microscopy (SEM). The catalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least six times without significant degradation in the activity.