Design, synthesis, and catalytic evaluation of aluminum‐incorporated magnetic core–shell mesoporous microsphere catalyst NiFe₂O₄@SiO₂@Al‐MS for the synthesis of functionalized indenopyrazolones

Abstract

A core-shell structured magnetic metal-mesoporous microsphere materials NiFe 2 O 4 @SiO 2 @Al-MS in which magnetic particles of NiFe 2 O 4 are core and ordered mesoporous silica are shell, incorporated with aluminum to modify acid-catalyzed reactions. The catalyst was synthesized by Pluronic P123 as a first surfactant and a small quantity of cetrimonium bromide as a template for assistant in acidic medium to create a porous layer. The structural characterization of the catalyst was assessed by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), energydispersive X-ray (EDX), vibrating-sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET) analyses. The catalyst demonstrated considerable magnetic properties, a unique mesoporous structure with great surface area (370.36 m 2 g À1 ), high-value recovery, and reusability. The catalyst performance was evaluated for the synthesis of indenopyrazolones via the condensation of ninhydrin, phenylhydrazine, and various aldehydes. The mild conditions for the synthesis, easy workup, and short reaction time are the considerable benefits of the reaction in the presence of Nife 2 O 4 @SiO 2 @Al-MS as a catalyst.