Stepwise synthesis of magnetic mesoporous silica nanoparticles decorated with SnO₂ quantum dots as an efficient, recyclable, and green nanocatalyst for the synthesis of benzo[a]pyrano[3,2‐c]phenazine derivatives

In this research, magnetic mesoporous silica nanoparticles decorated with SnO 2 quantum dots (M‐MSNs/SnO 2 [QDs]) were successfully synthesized and characterized using several advanced techniques including FT‐IR, XRD, FE‐SEM, EDS, elemental mapping, VSM, and BET. This study demonstrates the synthesis of benzo[a]pyrano[3,2‐c]phenazine derivatives via a four‐component reaction between 2‐hydroxy‐1,4‐naphthoquinone, ortho‐phenylenediamine, malononitrile, and benzaldehyde derivatives in the presence of M‐MSNs/SnO 2 (QDs) in ethanol as a green solvent. The proposed catalyst efficiently catalyzed the synthesis of these compounds with yields of 87–96% in 70–100 minutes. The presented method offers a cost‐effective and environmentally friendly approach with numerous advantages, including high product yields, simple operation, short reaction times, low‐cost purification, and facile catalyst recovery.