Fe2O3/SiO2-PW12nanoparticles: Highly efficient catalysts for the synthesis of pyrazolinederivatives

A new type of magnetically-recoverable catalyst was synthesized by the immobilization of H3PW12O40 on the surface of silica-encapsulated ?-Fe2O3 nanoparticles. A series of novel 1,3,5-triaryl pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in the presence of the ?-Fe2O3@SiO2-PW12nanoparticles, in high yields. The structures of compounds obtained were determined by IR and 1H NMR spectra. ?-Fe2O3@SiO2-PW12was recycled and no appreciable change in activity was noticed after three cycles.