A novel and efficient route for the syntheses of hydroxylated 2,3-diarylxanthones

• Author(s): Santos, Clementina M.M. ; Silva, Artur ; Cavaleiro, José
• Date: 2007
• Persistent ID: http://hdl.handle.net/10198/3240
• Origin: Biblioteca Digital do IPB
• Subject(s): Hydroxylated diarylxanthones; 3-bromo-2-styrylchromones; Heck reaction; Phenyltrimethylammonium tribromide; Demethylation
• Document Type: Article
• Language: English

Description

A novel, efficient and general route for the synthesis of hy-droxylated 2,3-diarylxanthones is described. 3-Bromo-2-styrylchromones, the key intermediate of this synthesis, is obtained by a Baker-Venkataraman rearrangement of appropriate 2’-cinnamoyloxyacetophenones, followed by a one-pot reaction with phenyltrimethylammonium tribromide. The Heck reaction of these bromochromones with substituted styrenes gives methoxylated 2,3-diarylxanthones. The cleavage of the methyl groups with BBr3 gives the desired hydroxylated 2,3-diarylxanthones.