The novel pyridinium chloride-functionalized MnCoFe2O4- SO3H nanoparticles, ( MnCoFe2O4@Niacin-SO3H)+Cl−, were synthesized by coating the sulfonic group on the surface of MnCoFe2O4@ Niacin. The activity of these nanoparticles was studied for the synthesis of tetrahydrodipyrazolopyridines and pyranopyrazole derivatives via the multi-component reactions of ethyl acetate, hydrazine, aldehydes, and ammonium acetate or malononitrile. The use of green solvent, easy separation of the catalyst from the reaction medium, easy deposition, high purity, and openness of products are some advantages of this procedure.
