Highly efficient and easy synthesis of biscoumarin catalyzed by pentafluoropropionic acid (PFPA) as a new catalyst in aqueous medium

Pentafluoropropionic acid efficiently catalyzes the one-pot reaction of 4-hydroxycoumarin and aryl aldehydes under mild reaction conditions to yield biscoumarin derivatives in high yields. The products were obtained in short reaction times. We believe this applicability of pentafluoropropionic acid with mentioned advantages makes our method superior over previous reported methods to the synthesis of biscoumarins.