A Facile Synthesis of Highly Functionalized 4-Arylcoumarins via Kostanecki Reactions Mediated by DBU

Abstract

An efficient synthesis of 4-arylcoumarins has been accomplished via Kostanecki reactions of 2-hydroxybenzophenones with acetic anhydride employing DBU at ambient temperature. Using the same strategy, several 2-acyloxybenzophenone derivatives were readily converted to 3,4-difunctionalized coumarins. This protocol offers a notable improvement in reaction conditions for coumarin synthesis and takes advantage of its synthetic capability, especially for highly functionalized 4-arylcoumarins with structural diversity.

Keywords

• 4-arylcoumarins
• Kostanecki reaction
• DBU
• 3,4-disubstituted coumarins
• one-pot reaction