Synthesis of Bis(indolyl)methane Derivatives Catalyzed by Recyclable Nano Fe3O4@ZrO2/SO42-

Background: Bis(indolyl)methane derivatives exhibit varied biological and pharmacological properties like antibacterial and antiangiogenic activities, acting as cytotoxic agents and tumor growth inhibitors. Several approaches of bis(indolyl)methane synthesis have been reported, most of them involving condensation of indoles with aldehydes or ketones in the presence of protic or Lewis acids. Also other catalysts like enzymes were used in this reaction that did not result in high yields. Still, there is a long way to modify this reaction by better ways. Methods: Due to massive applications of magnetic sulfated zirconia as a catalyst, we decided to study its abilities to synthesize bis(indolyl)methane derivatives. In this work, to increase the yield and lower the time of the reaction, we synthesized Fe3O4@ZrO2/SO42- as a heterogeneous nanocatalyst and used it in one pot reaction of aldehyde and indole to obtain bis(indolyl)methane derivatives. Results: An effective method for the synthesis of bis(indolyl)methane derivatives in high yields was developed by the use of Fe3O4@ZrO2/SO42- as a catalyst. The synthesis of bis(indolyl)methane by this catalysts resulted in short reaction times and high yields. Easy separation from the reaction mixture and capability of reusing heterogeneous nanocatalysts are the advantages of these type of catalysts. Fe3O4@ZrO2/SO42- as a magnetic recyclable heterogeneous nanocatalyst can be used 5 times with no significant loss of activity. Conclusion: According to the importance of bis(indolyl)methane derivatives in industrial applications and biological properties, we synthesized the sulfated zirconia nanoparticles as acidic heterogeneous magnetic catalyst by sol-gel method and used it in the synthesis of bis(indolyl)methane derivatives. It was found that products with high efficiency can be achieved in a relatively short period of time. This catalyst is more capable than many other heterogeneous magnetic catalysts and due to its advantages like thermal stability and also its chemical bonding of functions with surface that do not extract with changing solvent; it can be used widely in a variety of multi-component reactions.