Ferric (III) complex supported on superparamagnetic Fe3O4@SiO2 as a reusable Lewis acid catalyst: a new highly efficient protocol for the synthesis of acridinedione and spiroquinazolin-4(3H)-one derivatives

Nano-Fe3O4@SiO2-3,4-dihydroxybenzaldehyde/barbituric acid/phthalhydrazide-FeCl3 (nano-Fe3O4@SiO2-HBP-FeCl3) was prepared and authenticated by usual analytical and spectroscopic techniques. The prepared nano-Fe3O4@SiO2-HBP-FeCl3 was applied to acridinedione and spiroquinazolin-4(3H)-one derivatives under green conditions. In addition, this research offers several advantages such as very easy reaction conditions, simple work-up, excellent yields, high purity of the desired product, short reaction time and one-pot reaction to synthesize Fe3O4@SiO2-HBP-FeCl3. The recycling studies revealed that catalyst could be easily recovered using an external magnet and reused five times without significant loss of its catalytic activity.