علی اکبری

Silica-supported boron trifluoride (BF3•SiO2) is an efficient, readily available, and reusable catalyst for the synthesis of 2-amino-5-oxo-4-aryl-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile or carboxylic acid ethyl ester derivatives by condensation of 4-hydroxycoumarin, an aldehyde, and an alkylnitrile. Heterocyclic Communications