Nitric Acid → 6-Bromo-2-nitropyridin-3-ol

Participants

Reaction Steps

To a suspension of 6-bromopyridin-3-ol (2.5 g, 14.4 mmol) in acetic acid (20 mL) at 0° C. was added fuming nitric acid (0.9 mL, 22.4 mmol). The reaction mixture was stirred at room temperature for 1 hour and then at 60° C. for 1 hour. The reaction mixture was cooled to 0° C. and 10M aqueous hydroxide was added dropwise until pH 4-5 (ca 25 mL). The resulting mixture was diluted with water and partially concentrated under reduced pressure. The residue was extracted twice with EtOAc. The organic fractions were combined and washed with water and brine, dried over Na2SO4, filtered and concentrated. The residue was azeotroped with toluene to give 6-Bromo-2-nitropyridin-3-ol as an orange solid (2.2 g, 71%). 1H NMR (400 MHz, DMSO-d6): δ 11.92 (s, 1 H); 7.86-7.83 (d, J=8.6 Hz, 1 H); 7.61 (d, J=8.6 Hz, 1 H).

Provenance & Evidence