Application of a biological-based nano magnetic catalyst in the synthesis of bis-pyrazols and pyrano[3,2-c] pyrazoles

Nowadays, the knowledge-based designing, synthesis and applications of nano magnetic particles (NMPs) are of great demand, and a wide variety of nanostructured magnetic catalysts have been used because of their recycle and reusability, high activity and selectivity in chemical processes. Application of recycle and reusable catalysts or catalytic systems in the chemical processes is in close agreement with the green chemistry disciplines because of their using will be decreased the activation energy, waste of reactions, and energy consumption. The development of nano magnetic catalysts and their roles in the pollutionprevention in our environment at the past, present and future have been extensively reviewed [1-3]. {Fe3O4@SiO2@(CH2)3-thiourea dioxide-SO3H/HCl} a newly reported nano magnetic coreshell supported solid acid catalyst was successfully employed at the preparation of 4,4 - (arylmethylene)bis(1H-pyrazol-5-ol) and pyrano[3,2-c] pyrazole derivatives. The presented methods are very efficient and high-yielding. Also, the catalyst exhibited powerful potent of reusability in both cases of the reactions (Figure1).