反应详情

To a solution crude of 5-ethanesulfonyl-pyridin-2-ol prepared above, and sodium acetate (3.74 g, 45.6 mmol) in acetic acid (50 mL) was added a solution of bromine (7.3 g, 46.0 mmol) in acetic acid (10 mL) dropwise over a period of 1 hour. After being stirred at room temperature overnight, additional bromine (7.3 g, 46.0 mmol) in acetic acid (10 mL) was added dropwise to the reaction mixture over a period of 1 hour. After being stirred overnight, the reaction mixture was warmed to 30° C. and stirred for 2 hours. The mixture was concentrated in vacuo to remove the solvent. The residue was triturated with water (100 mL). The solid was collected by filtration, washed with a dilute solution of sodium thiosulfate and dried in vacuo to afford 3-bromo-5-ethanesulfonyl-pyridin-2-ol (9.1 g, 75%, two steps) as a white solid (reference: Bargar, T. M. et al., J. Heterocyclic Chem. 22 (1985) 1583-1592).

1. stirringAfter being stirred overnight
2. temperaturethe reaction mixture was warmed to 30° C.
3. stirringstirred for 2 hours
4. concentrationThe mixture was concentrated in vacuo
5. customto remove the solvent
6. customThe residue was triturated with water (100 mL)
7. filtrationThe solid was collected by filtration
8. washwashed with a dilute solution of sodium thiosulfate
9. customdried in vacuo