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 1 H -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. • Novel magnetic copper nanoparticle catalyst, Cu@β-CD@AlFe 2 O 4 NPs. • The efficient green synthesis of 1 H -pyrazolo[1,2- b ]phthalazine-5,10-diones. • Three-component condensation reaction involving malonitrile, aromatic aldehydes, and phthalhydrazide. • The synthesized by anchoring copper nanoparticles onto β -cyclodextrin-modified aluminum ferrite (AlFe 2 O 4 ) under solvent-free conditions and utilizing microwave irradiation at room temperature. • The Cu@ β -CD@AlFe 2 O 4 NPs demonstrated excellent reusability, maintaining catalytic efficiency across multiple reaction cycles without significant degradation in performance.