Phosphorus Pentoxide-Methanesulfonic Acid → 4-Chloro-2-methoxy-9H-fluoren-9-one

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere, to 2′-chloro-4′-methoxybiphenyl-2-carboxylic acid (65.4 g) was added an Eaton reagent (phosphorus pentoxide-methanesulfonic acid (weight ratio 1:10) solution, 330 ml), and the mixture was stirred at an oil bath temperature of 100° C. for 1 hr. The reaction mixture was ice-cooled, water (650 ml) was slowly added dropwise, and the mixture was stirred at room temperature for 1 hr. The precipitated solid was collected by filtration, and washed with water (500 ml). The obtained solid was air-dried overnight to give the title compound (92.0 g).

Provenance & Evidence