6-Chloro-2-naphthoic acid

5773-80-8

5042-97-7

6-Bromo-2-naphthalenecarboxylic acid (3.0 g, 11.47 mmol) was used as a raw material and suspended in degassed DMF (45 mL) with CuCl (11.7 g, 114.64 mmol) and CuI (2.19 g, 11.50 mmol) under argon protection. The reaction mixture was heated to reflux for 4 h under light protection. After completion of the reaction, it was cooled to room temperature and the reaction solution was poured into water (200 mL) and extracted with ethyl acetate (2 x 500 mL). The organic phases were combined, washed sequentially with water (4 × 500 mL) and saturated saline (1 × 500 mL), dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure. The residue was ground with acetonitrile and the resulting solid was recrystallized by ethyl acetate to give pure 6-chloro-2-naphthalenecarboxylic acid (Compound 32, 2.2 g, 93% yield) as an off-white solid. hPLC retention time t R 6.47 min.