75630-53-4Relevant articles and documents
Pyrolitic Elimination of Hydrogen Halide and Halogen from 2,3-Dihalogenoketones
Donnely, John A.,Quigley, Killian
, p. 1299 - 1305 (2007/10/02)
The thermal elimination of hydrogen chloride from 2'-hydroxychalcone dichlorides occured in two stages, initially forming 3-chloroflavones and then flavones; α-chloro-2'-hydroxychalcones, the likely intermediates in the formation of 3-chloroflavones, also yielded the same products.The pyrolysis of 2'-hydroxychalcone dibromides resulted in debromination as well as dehydrobromination with the consequent appearence of brominated flavones among the products.The formation of 3-bromoflavones was not observed but the isomeric (E)-α-bromo-2'-hydroxychalcones thermally isomerized to their (Z)-isomers and then underwent cyclization and dehydrobromination.The bromide were considerably more reactive than the dichlorides but, as a synthetic procedure, the pyrolysis of the dichlorides is cleaner and more productive.
