Magnetic copper nanoparticle catalyst on β-cyclodextrin-modifed AlFe2O4 for efficient green synthesis 1H-pyrazolo[1,2-b]phthalazine-5,10-diones

This study reports a green, efficient synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones using a novel magnetic copper nanoparticle catalyst, Cu@β-CD@AlFe₂O₄. The catalyst, prepared by anchoring copper onto β-cyclodextrin-modified AlFe₂O₄, was characterized via SEM, TEM, XRD, and FT-IR. Reactions with malonitrile, aromatic aldehydes, and phthalhydrazide were carried out under solvent-free microwave conditions at room temperature, yielding remarkably high product yields (89–97 %) over 18 examples. The catalyst is highly reusable, retaining efficiency after five cycles. This work showcases the potential of magnetic nanocatalysts for eco-friendly organic synthesis.