Halogenation of fluorinated cyclic 1,3-dicarbonyl compounds: new aspects of synthetic application

In order to elaborate on an approach towards 2-(fluoroacyl)phenols being the superior alternative to the conventional Fries-rearrangement based methodology, the behaviour of cyclic fluorinated 1,3-dicarbonyls in reactions with halogenating agents was examined. The synthetic relevance of the polyhalogenated compounds obtained was demonstrated by the synthesis of several new heterocycles. An aromatization via a halogenation–dehydrohalogenation sequence proved to be a rewarding synthetic route to 2-(fluoroacyl)phenols and previously unknown 3-(fluoroacyl)thiochromones. The structure of one of the synthesized compounds was confirmed by X-ray diffraction analysis.