N-Propyl benzoguanamine sulfonic acid supported on magnetic Fe3O4 nanoparticles: a novel and efficient magnetically heterogeneous catalyst for the synthesis of 1,8-dioxo-decahydroacridine derivatives

In this study, N-propyl-benzoguanamine-SO3H-stabilized magnetic nanoparticles were prepared as a new heterogeneous acid catalyst in accordance with the principles of green chemistry. The new catalyst is used for the synthesis of derivatives of 1,8-dioxo-decahydroacridine in one-stage via four-partial condensation reactions between aromatic aldehydes, dimedone and ammonium acetate or aniline with high yield and short reaction times. The structure of the nanoparticles obtained via Fourier transform infrared spectroscopy (IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), energy-dispersive X-ray analysis (EDXA), X-ray diffraction (XRD), thermogravimetry analysis (TGA), vibrating sample magnetometry (VSM), atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) is assessed. The results show that the size of the synthesized magnetic nanoparticles is about 25 nm. The heterogeneous catalyst can be easily recovered by an external magnet and can be reused several times without a significant loss of catalytic activity.