Potassium Nitrate → 5-nitro-1H-indazole-3-carboxylic Acid

Participants

Reaction Steps

To a suspension of indazole-3-carboxylic acid (compound 53, 3.0 g, 18 mmol) in 18 mL of concentrated sulfuric acid at 0 C was added potassium nitrate (2.0 g, 18 mmol). The reaction was stirred overnight at room temperature, poured into 150 mL of ice and extracted three times with ethyl acetate. The combined organic layer was washed with brine, dried and concentrated to give compound 54 (2.9 g) as the major isomer.

Provenance & Evidence