Acetic Anhydride → 5-Bromo-6-chloropyridin-3-yl acetate

Temperature

0 °C

To a stirred mixture of 5-bromo-6-chloropyridin-3-amine (7.57 g, 36.5 mmol) in tetrafluoroboric acid (70 mL, 536 mmol, 48 wt. % solution in water) at 0° C. was added sodium nitrite (2.64 g, 38.3 mmol) in water (70 mL) slowly over 10 min. The reaction mixture was stirred at 0° C. for 1 h. The reaction mixture was filtered and washed with water. The resulting solid was dissolved in acetic anhydride (70 mL, 742 mmol) and stirred at 70° C. for 1 h. The reaction mixture was cooled to room temperature, diluted with EtOAc, washed with water, washed with sat. sodium chloride, dried over magnesium sulfate, filtered, and concentrated. The resulting crude product was purified by silica gel chromatography to give 5-bromo-6-chloropyridin-3-yl acetate. MS (ESI, pos. ion) m/z: 249.9 and 251.9 (M+1).

1. filtrationThe reaction mixture was filtered
2. washwashed with water
3. stirringstirred at 70° C. for 1 h
4. temperatureThe reaction mixture was cooled to room temperature
5. washwashed with water
6. washwashed with sat. sodium chloride
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe resulting crude product was purified by silica gel chromatography

ORD record

ord-0bf1f5480a87490f8765427036d311ff

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08637500B2