TRIPHENYPHOSPHINE-MEDIATED EFFICIENT SYNTHESIS OF FUNCTIONALIZED 2-OXO-2H-CHROMENES

Abstract

Dimethyl acetylenedicarboxylate reacts smoothly with phenol derivatives, such as 4-chloro-3,5-dimethylphenol, 2-chloro-5-methylphenol, 4-chloro-2-methylphenol, 2,4-dichlorophenol, or 2-bromophenol in the presence of triphenylphosphine to produce highly functionalized 2-oxo-2 H-chromenes (coumarins) in moderate yields.

Keywords:

• 2-Oxo-2H-chromenes
• acetylenic ester
• aromatic substitution
• triphenylphosphine