γ-Fe2O3@HAp@PBABMD@Cu magnetic nanoparticles: Efficient, green, and recyclable novel nanocatalyst for the synthesis of densely functionalized pyrrole-pyrido[2,3-d]pyrimidine hybrids

A green heterogeneous nanocatalyst, Cu(II)-PBABMD complex immobilized on core-shell magnetic gamma-Fe2O3@HAp, was successfully designed, synthesized, and characterized by FTIR, XRD, FESEM, EDX, VSM, TGA, BET, ICP-OES, and TEM techniques. The magnetic Cu(II) nanocatalyst was employed as a novel, ecofriendly, recyclable, and safe catalyst for the one-pot, three-component condensation of 6-amino-2-thioxo-2,3-dihydropyrimidin-4(1H)-one, 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile and aromatic aldehydes to produce new pyrido[2,3-d]pyrimidine derivatives, in refluxing EtOH with excellent yield (90-97%) and short reaction time (8-13 min). The nanocatalyst was used and recycled in eight runs without significant leaching or loss of its catalytic activity.