Utilization of "2-Pyrrolidone Hydrotribromide" in the Synthesis of Flavones

Article abstract of DOI:10.1246/bcsj.58.1599

The reaction of flavanone with "2-pyrrolidone hydrotribromide" in tetrahydrofuran gave 3-bromoflavanone in a good yield.On the other hand, flavone was obtained in 97percent yield when this reaction was carried out in dimethyl sulfoxide at 80 deg C.Under the same conditions, most flavones were obtained from the corresponding flavanones in high purity and good yiels.