Synthesis of novel biologically active pyridonaphthyridine derivatives by employing Fe3O4/SiO2/CuO as a magnetically recoverable nanocatalyst

Abstract

In this investigation, we successfully synthesized a fused pyridonaphthyridine, a newly identified class of fused heterocyclic compounds, through an efficient multicomponent reaction. The methodology involved utilizing 1-aminonaphthalene, 2-(1,3-diimino-1,3-dihydro-2H-inden-2-ylidene)malononitrile, alkyl bromides and activated acetylenic derivatives within an aqueous medium at ambient temperature. Notably, the process was facilitated by a reusable catalyst composed of Fe₃O₄/SiO₂/CuO. The antioxidant activity of the synthesized compounds, which could be attributed to the naphthyridine core, was measured by two procedures: DPPH and FRAP. The compound 5a showed the best antioxidant activity relative to other compounds. Additionally, a theoretical study was conducted using density functional theory (DFT) with the B3LYP functional in conjunction with the 6-311G(d,p) basis set to investigate the electronic structures, geometries, and reactivity properties of the molecular compounds. Results revealed that compound 5e showed remarkable reactivity due to its lower energy gap and higher electrophilicity. Furthermore, density functional theory calculations were used to visualize the images of HOMO and LUMO orbitals.