Fe3O4@nano-cellulose/Ti(IV): An efficient and natural-based magnetic nano-catalyst for the synthesis of functionalized pyrimido [4,5-b] quinolines in aqueous media

A simple, efficient, and high yielding one-pot protocol for the synthesis of pyrimido [4,5-b] quinoline derivatives has been developed. Pyrimido [4,5-b] quinolines were synthesized by three component reaction of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, dimedone and various substituted aldehydes using Fe3O4@NCs/Ti(IV) as a magnetic natural-based catalyst in water at 70 °C. Several advantages of this protocol are good yields, short reaction times, easy work-up, recyclability and the environmentally benign of the catalyst. 6-Amino-2-(methylthio)pyrimidin-4(3H)-one as an important substrate was synthesized, purified, identified and then applied for the synthesis of pyrimido [4,5-b] quinolines. The structures of the products were confirmed by IR, 1H NMR and 13C NMR spectra.