5-Bromo-2-(2-fluoro-4-methoxyphenoxy)benzoic acid → 7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one

Participants

Reaction Conditions

Reaction Steps

5-bromo-2-(2-fluoro-4-methoxyphenoxy)benzoic acid (28.5 g, 84 mmol) and polyphosphoric acid (205 g, 2089 mmol) were combined and heated at 125° C. for two hours. The solution was diluted with water (1 L) and filtered. The solids were washed well with 2N NaOH, then with water. The solids were then dried under vacuum to afford 7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one as an off white solid. MS m/z=323.0 [M+H].

Provenance & Evidence