Water → 6-Fluoro-4-hydroxy-3-methyl-naphthalene-2-carboxylic acid

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Reaction Steps

A solution of 2-[1-(4-fluoro-phenyl)-meth-(E)-ylidene]-3-methyl succinic acid (28 g, 118 mmol) in trifluoromethanesulfonic acid (140 mL) was stirred at room temperature for 16 h. The resulting mixture was carefully poured into ice cooled water with continuous stirring to give a solid precipitate, which was filtered, washed with water and dried in vacuo to yield 6-fluoro-4-hydroxy-3-methyl-naphthalene-2-carboxylic acid (28 g, >100% crude) as yellow solid. This crude product was used in the next step without further purification. MS calcd. for C12H8FO3 [(M−H)−] 219, obsd. 218.9.

Provenance & Evidence