Poly(N‐vinyl‐2‐pyrrolidone)‐supported ferric chloride: An effective reusable heterogeneous catalyst for one‐pot synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones via three‐component Biginelli reaction

An environmentally benign three‐component Biginelli protocol for the one‐pot synthesis of substituted 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones using an accessible, nontoxic, easy to handle, and recoverable macromolecular Lewis acidic catalyst is developed. N,N′‐methylene bis‐acrylamide‐cross‐linked poly(N‐vinyl‐2‐pyrrolidone) (MBA‐PVNP) as beads was used as a support for ferric chloride, resulting in a heterogeneous and reusable catalyst. The reusability test of the heterogenized version of ferric chloride, PNVP/FeCl3 ascertained that the obtained catalyst can be easily separated from the reaction mixture by filtration and reused several times with no great decline of activity. An environmentally benign three‐component Biginelli protocol for the one‐pot synthesis of substituted 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones using an accessible, non‐toxic, easy to handle, and recoverable macromolecular Lewis acidic catalyst is developed.