2'-Methyl-biphenyl-2,4'-dicarboxylic acid → 4-methyl-9-oxo-9H-fluorene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 2′-methyl-biphenyl-2,4′-dicarboxylic acid (1.94 g) and polyphosphoric acid (50 g) was stirred at 180° C. for 3 hr. The reaction mixture was cooled to room temperature, water (100 ml) was slowly added dropwise, and the mixture was further stirred at room temperature for 10 min. This suspension was filtered, and the obtained solid was successively washed with water (50 ml) and 50 v/v % aqueous methanol solution (50 ml). The obtained solid was air-dried, and dried under reduced pressure at 80° C. to give the title compound (1.745 g, 97%).

Provenance & Evidence