Sonochemical one pot synthesis of novel spiroacridines catalyzed by magnetically functionalized Fe3O4 nanoparticles with chitosan as a reusable effective catalyst

A facile one-pot and three-component economical synthesis of spiroacridine using acenaphthoquinone, different anilines and dimedone in the presence of Fe3O4@CS-SO3H NPs catalyst under ultrasonic irradiation is described. Firstly, the Fe3O4@CS NPs were prepared from reaction of chitosan with Fe3O4 NPs. Afterwards, treatment of Fe3O4@CS NPs with chlorosulfonic acid leads to the formation of Fe3O4@CS-SO3H NPs. Compared to the conventional methods, the ultrasound procedure showed several advantages including mild reaction conditions, high yield of products, short reaction times, and reusability of the catalyst. The core-shell structure and the composition of the produced magnetic nanocatalyst were analyzed using FT-IR, XRD, VSM, SEM and EDX techniques.