2-(4-Chloro-2-methylphenyl)benzoic acid → 2-Chloro-4-methyl-fluoren-9-one

Participants

Reaction Conditions

Reaction Steps

Under anhydrous calcium chloride drying conditions, a mixture of 4′-chloro-2′-methyl-biphenyl-2-carboxylic acid (21.60 g) and Eaton's reagent (7.7 w/w % solution of phosphorus pentoxide in methanesulfonic acid) (170 ml) was stirred at 100° C. for 2.5 hr. The reaction mixture was ice-cooled, water (500 ml) was slowly added dropwise, and the mixture was further stirred at room temperature for 10 min. This suspension was filtered, the obtained solid was mixed with 30 v/v % aqueous ethanol solution (200 ml), and the slurry was stirred at room temperature for 10 min, and filtered. The obtained solid was air-dried and dried under reduced pressure at 80° C. to give the title compound (19.744 g, 99%).

Provenance & Evidence