Magnetite and Cerium Dioxide Nanocomposites as Catalysts for Cyclocondensation Reactions of β-Dicarbonyl Compounds in the Synthesis of Pyrimidines and m-Terphenyls

The effective methods for obtaining Fe 3 O 4 /CeO 2 , Fe 3 O 4 (TEOS)CeO 2 nanocomposites with cerium dioxide content from 38 to 82% and from 32 to 70%, respectively were developed, their morphological, structural and magnetic studies were carried out. Cerium dioxide and magnetite composites have a crystalline structure and ferromagnetic properties characteristic for magnetite with non-magnetic impurities. Thereby it can be easily separated from the reaction medium by means of a permanent magnet. The nanocomposites exhibit catalytic activity in cyclocondensation reactions: the interaction of chalcones with acetoacetic ester in an alkaline medium in the presence of the 1.6 wt % resulting nanocomposite leads to the formation of m-terphenyl derivatives in one-stage reaction, and in the condensation reaction with the formation of the 4,6-dimethyl- N -(4-methyl-3-nitrophenyl)pyrimidine-2-amine and 4,6-dimethyl- N -(2-methyl-5-nitrophenyl)pyrimidine-2-amine, the yield of the target product was increased to 52 and 96.8%, respectively. The resulting composites can be used repeatedly, providing sufficiently high yields of the target product.