Green synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazoles] using Fe(3)O(4)@l-arginine as a robust and reusable catalyst.

The synthesized Fe(3)O(4)@l-arginine showed strong catalytic performance in the one-pot synthesis of spiropyranopyrazoles via the reactions of hydrazines, β-keto esters, isatins, and malononitrile or ethyl cyanoacetate under solvent-free conditions. The biologically active heterocyclic compounds including spiropyranopyrazole derivatives were efficiently synthesized in short reaction times and excellent yields in the presence of Fe(3)O(4)/l-arginine at room temperature. The highlighted features of the Fe(3)O(4)@l-arginine nanocomposite are highly stable, easy to separate, low loading, cost-effective with easy preparation and reusability of the catalyst. The heterogeneous nanocomposite was fully characterized by SEM, EDX, FT-IR, XRD and TEM analysis.