Water → 2,7-Difluoro-3-methyl-9H-fluorenone

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of methyl 2-(3-methyl-4-fluorophenyl)-5-fluorobenzoic acid (6.5 g, 26.2 mmol) and polyphosphoric acid (30 g) was heated at 180° C. for 2 h. After the mixture had cooled to 80° C., it was poured into water (200 mL), and extracted with ethyl acetate. The combined extracts were washed with brine, dried over MgSO4, treated with charcoal, and concentrated. Chromatography on silica gel using 20% toluene in hexane provided 2 g (33%) of the desired ketone.

Provenance & Evidence