Methyl iodide → 2-Bromo-3-methoxypyridine

To a stirred mixture of 2-bromo-3-pyridinol (71.0 g) and pulverized KOH (77.8 g) in DMSO (500 mL) at 55°-60° C. and under N2 atmosphere was added dropwise a solution of CH3I (72.4 g) in DMSO (100 mL). After the addition was complete, the reaction was maintained at 55°-60° C. for 1/2 h. The mixture was then poured into ice water (800 g) and the precipitate filtered. The precipitate was triturated with Et2O (3×500 mL) and the combined extracts treated in turn with 1 N NaOH (500 mL), water (500 mL), 1 N HCl (3×250 mL), and sat. NaCl solution (500 mL). The organic phase was dried with anhydrous MgSO4, filtered, and concentrated under reduced pressure to afford 2-bromo-3-methoxypyridine (52.3 g; 68%).

1. customat 55°-60° C.
2. additionAfter the addition
3. temperaturethe reaction was maintained at 55°-60° C. for 1/2 h
4. filtrationthe precipitate filtered
5. customThe precipitate was triturated with Et2O (3×500 mL)
6. additionthe combined extracts treated in turn with 1 N NaOH (500 mL), water (500 mL), 1 N HCl (3×250 mL), and sat. NaCl solution (500 mL)
7. dry with materialThe organic phase was dried with anhydrous MgSO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure

ORD record

ord-7ae05d99950c473d90d6b54c23f6bb52

Source dataset

uspto-grants-1990_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04954502