An efficient one-pot synthesis of flavones

✍ Scribed by Chin Fei Chee; Michael J.C. Buckle; Noorsaadah Abd. Rahman

• Publisher: Elsevier Science
• Year: 2011
• Tongue: French
• Weight: 221 KB
• Volume: 52
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2011.04.022

✦ Synopsis

Flavones were prepared using a one-pot procedure starting from the corresponding 2 0 -hydroxyacetophenones. The latter were treated with 3 equiv of aroyl chloride in wet K 2 CO 3 /acetone (1% w/w water) to afford a good yield of flavone and a smaller amount of 3-aroylflavone. Evidence was obtained that the reaction proceeds via a triketone intermediate. When the reactants were heated in 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and pyridine, the 3-aroylflavone was obtained exclusively. Use of a stoichiometric amount of aroyl chloride afforded only the corresponding flavone.