A new general approach to 4-substituted-3-halo-2-quinolones

A general procedure for the preparation of 4-substituted-3-halo-2-quinolones (halo = F, Cl, Br) utilizing 2-halo diethylphosphonoacetic acids (halo = F, Cl, Br) and o-aminophenylketones as the starting materials is described. The title compounds are obtained by an intramolecular Horner–Wadsworth–Emmons olefination of halogen-containing N-acyl-o-aminophenylketones. The transformation process is generally applicable under mild conditions.

Graphical abstractA general and efficient procedure for the preparation of 4-substituted-3-halo-2-quinolones by an intramolecular Horner–Wadsworth–Emmons olefination under mild conditions.Figure optionsDownload full-size imageDownload as PowerPoint slide