An efficient synthesis of pyrimido[4,5-b]quinoline and indenopyrido[2,3-d]pyrimidine derivatives in the presence of Fe3O4@nano-cellulose/Sb (V) as a bio-based magnetic nano-catalyst

In this study, an eco-friendly approach has been introduced for the synthesis of pyrimido[4,5-b]quinolones and indenopyrido[2,3-d]pyrimidines. This synthesis was done via a three component coupling of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, 1,3-indanedione/dimedone and aromatic aldehydes using Fe3O4@nano-cellulose/Sb(V) as catalyst under solvent-free condition at 70 °C by electrical mortar-heater. The catalyst was separated from the reaction mixture by an external magnet and reused for subsequent reactions. The present procedure offers many advantages such as high yield, easy work-up, simple isolation of catalyst by external magnet and high reusability of the it. The structure of the obtained pyrimido[4,5-b]quinolones and indenopyrido[2,3-d]pyrimidines products were studied by FT-IR, 1H-NMR and 13C-NMR spectroscopic data.