2-bromo-4-nitropyridin-3-ol synthesis

Yield:-

Reaction Conditions:

with sulfuric acid;nitric acid at 0; for 12 h;

Steps:

36.e
To a solution of 13g (73.2mmol) 2-bromo-3-pyridinol (Fluka 18292) in 40ml of conc. sulfuric acid 5.1 ml (74mmol) of nitric acid (65%) are added at 0°C. The reaction mixture is stirred at 0°C for 12h, then poured on water and extracted 2x with EtOAc. The combinded organic layers are washed with water and saturated NaCl solution, dried over MgSO₄, filtered and the filtrate is concentrated in vacuo. The residue is purified by chromatography (silicagel, EtOAc) to afford 5.3g of 2-bromo-4-nitro-pyridin-3-ol and 2g of 2-bromo-6-nitro-pyridin-3-ol.

References:

Novartis AG EP1900729, 2008, A1 Location in patent:Page/Page column 24