LAUSR

Abstract An efficient method for the synthesis of functionalized 4H-chromenes via a one-pot three-component condensation reaction of a 2-hydroxybenzaldehyde with an active methylene compound and a carbon-based nucleophile in the presence of SrFe12O19 as catalyst under solvent-free at 80 °C condition has been described. SrFe12O19 was an efficient, green, and reusable magnetic nanoparticles as heterogeneous catalyst with the average particles size of 70 nm which can be recycled and readily separated from the reaction mixture using an external magnet. High product yields, simple work-up procedure, solvent-free conditions and characterization of the sensing properties of compound 4a for detection of Fe3+ ion are the main advantages of this procedure. The sensing ability of compound 4a was examined upon addition of a wide variety of cations both visually and by UV–Vis spectroscopy. The increase in UV–Vis absorbance was linearly proportional to the concentration of Fe3+ with a detection limit of 1.0 × 10−7 M. Moreover, the chemosensor exhibited an obvious color change from white to yellow in the presence of Fe3+ in EtOH solution.