۳,۴-Dihydropyrano [C] chromene Synthesis Using Fe۳O۴@SiO۲-SO۳H Magnetic Nanocatalyst

Synthesis of ۴H-chromene and its derivatives has attracted great interest due to their biological and pharmacological activities. Here, a simple and practical method was employed for synthesizing ۳,۴-Dihydropyrano[c]chromene derivatives, which have found medicinal applications. This method involves reacting ۴-hydroxycoumarin and malonitrile with an aromatic aldehyde in the presence of Fe۳O۴@SiO۲-SO۳H nanocatalyst and methanol as a green solvent. The prepared catalyst was characterized by FT-IR, XRD, BET, VSM, and SEM. The reaction was optimized for four variables of benzaldehyde derivatives, solvent type, temperature, and catalyst loading. The highest ۳,۴-Dihydropyrano [c]chromene yield of ۹۸% was obtained with ۱ mmol of ۳-nitrobenzaldehyde and ۰.۰۵ g of Fe۳O۴@SiO۲-SO۳H at ۸۰ °C in methanol solvent after ۲h. Notably, the saturation magnetization of Fe۳O۴@SiO۲-SO۳H nanocomposites is sufficient for magnetic separation using an external magnet. This method yields excellent results with easy separation of catalyst. The recyclability test for five consecutive runs showed negligible loss in catalytic activity.

کلیدواژه ها:

۴-Hydroxycoumarin ، Malononitrile ، Aromatic aldehyde ، nanocatalyst