Sulfonated-silica-coated cobalt ferrite (CoFe2O4) magnetic nanoparticles (MNPs-SiCoFe-SO3H) are efficient heterogeneous catalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazoline derivatives in absence solvent. The effects solvent, temperature, catalyst amount on reaction investigated. easy separation, reusability catalyst, simplicity procedure, mild conditions, good...