One class of heterocyclic compounds known to display various pharmaceutical and biological activities are pyridines.1 Synthesis of 1,4-dihydro-pyridines, such as acridine derivatives is an important and useful task in organic chemistry.2 Metal oxide nanostructures, including iron, have gained significant importance as they have been demonstrated to be applicable in catalytic technology which cannot be usually achieved by their bulk counterparts.3 In continuation of our interest in the application of magnetic nanoparticles supported with functionalized 4-amino-pyridine silica (MNPs@SiO2-Pr-AP) are investigated as catalysts in organic synthesis, we report here a convenient method for the preparation of acridines from naphthalen-1-amine, dimedone and various aldehydes in the presence of MNPs@SiO2-Pr-AP under solvent-free conditions (Scheme 1).
