Synthesis of furo[3,2-c]coumarins under microwave irradiation using nano-CoFe₂O₄@SiO₂–PrNH₂ as an efficient and magnetically reusable catalyst

CoFe2O4@SiO2–PrNH2 nanoparticles have been used as an efficient and magnetically recoverable catalyst for the preparation of trans-3-aryl-2-(4-bromobenzoyl)-2,3-dihydro-4H-furo[3,2-c]chromen-4-ones by multicomponent reaction of 2,4'-dibromoacetophenone, aromatic aldehydes, and 4-hydroxycoumarin in the presence of pyridine in ethanol under microwave irradiation. It was demonstrated by 1H NMR spectroscopy and single crystal analysis that the obtained furo[3,2-c]coumarins were the trans-isomers.