One-pot Synthesis of Spirooxindole Derivatives Catalyzed by Bi2Fe4O9 Nanoparticles

In this study regarding the catalytic application of Bismuth Ferrite nanoparticles in the synthesis of heterocyclic compounds, we synthesized Bi₂Fe₄O₉ nanoparticles by sol-gel combustion method from bismuth nitrate pentahydrate [Bi(NO₃)₃.5H₂O] and iron nitrate nonahydrate [Fe(NO₃)₃.9H₂O] as starting materials. Structural and microstructural were characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy(FESM), Vibrating-Visible Spectroscopy(VSM) and infrared spectroscopy (IR). The average size of nanoparticles was determined 36, 3 nm, by XRD and Scherer’s equation. The results show that the pure phase of Bi₂Fe₄O₉ can be formed by this method. Then it is used in the one- pot synthesis of spirooxindole derivatives via three-component reaction of isatins, malononitrile and 1,3- dicarbonyl compounds in water as a green solvent in the temperature of 80℃. The reaction yields 88-98 percentages of the products. The catalyst was reused several times in the same reaction yielding unchanged products.