Potassium Carbonate → 5-(4-Acetylphenyl)-6-chloro-1H-indazole-3-carboxylic acid

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Reaction Steps

To a mixture of 5-bromo-6-chloro-1H-indazole-3-carboxylic acid (200 mg, 0.73 mmol) and 4-acetylphenylboronic acid (131 mg, 0.80 mmol) in toluene (2 mL) and EtOH (1 mL) was added 2 N aqueous potassium carbonate solution (1.45 mL, 2.90 mmol). The resulting mixture was degassed with N2 for 10 minutes, treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (29 mg, 0.036 mmol), and heated to reflux for 16 hours. The cooled reaction was quenched with saturated NH4Cl and the mixture was filtered. The filtrate was acidified with 1 N HCl to pH 5 and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo. The resulting crude material was purified by reverse phase chromatography (Biotage C18 column, 0-40% MeCN/water) to give the title compound (82 mg, 40% yield) as a solid. MS (ES+) 315.0 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 8.14 (s, 1H), 8.01 (d, J=8.39 Hz, 2H), 7.82 (s, 1H), 7.57 (d, J=8.20 Hz, 2H), 2.60 (s, 3H).

Provenance & Evidence