Fe3O4@SiO2/BiPy‏2+2Cl– nanocomposite promoted rapid synthesis of Pyranopyrazole and Octahydroquinazoline derivatives

Fe3O4@SiO2/bipyridinium chloride nanocomposite, Fe3O4@SiO2/BiPy+22Cl-, as a magnetically separable and recyclable heterogeneous catalyst was used for the one-pot synthesis of pyranopyrazole and octahydroquinazoline derivatives via multi-components cyclocondensation reaction under solvent free conditions. The catalyst was recovered by simple magnetic decantation and can be recycled several times with no significant loss of its catalytic activity. The results showed that the desired products were obtained with high efficiency, rapid, simple, and eco-friendly.