Synthesis, characterization and application of Fe3O4@SiO2@Tannic acid nanoparticles: A novel and magnetically recyclable catalyst for one-pot synthesis of novel 5-pyrazolin-1,2,4-triazolidine-3-ones (thiones)

Abstract

Tannic acid-functionalized silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2@Tannic acid) were synthesized and characterized by X-ray powder diffraction (XRD), X-ray spectroscopy (EDX), transmission electron microscope (TEM), field emission scanning electron microscope (FE-SEM), vibrating sample magnetometry (VSM) and fourier transform infrared spectroscopy (FT-IR). Fe3O4@SiO2@Tannic acid supply an eco-friendly procedure for the synthesis of some novel 5-pyrazolin-1,2,4-triazolidine-3-ones or thiones through one-pot reaction of thiosemicarbazide (hydrazinecarbothioamide), and synthetized pyrazolecarbaldehydes in accordance with green chemistry rules, such as using an efficient catalyst, reacting in water solvent and room temperature. In the other study, this novel synthesized magnetically reusable catalyst was introduced as a new avenue for the synthesis of 5-pyrazolin-1,2,4-triazolidine-3-ones or thiones as a novel heterocyclic compounds, using the reaction between synthetized pyrazolecarbaldehydes, thiosemicarbazide or semicarbazide in aqueous media. These compounds were obtained in high yields and short reaction times. The catalyst could be easily recovered and reused for six cycles with almost consistent activity. The structures of the synthesized 5-pyrazolin-1,2,4-triazolidine-3-one or thione compounds were confirmed by 1H NMR, 13C NMR and FTIR spectral data and elemental analyses.