反应详情

Add N-methylmorpholine (6 mL, 52 mmol) and isobutylchloroformate (3.5 mL, 26.9 mmol) to a solution of 6-fluoropyridine-2-carboxylic acid (3.8 g, 26.9 mmol) in methylene chloride at 0° C. After 15 minutes add O,N-dimethylhydroxylamine hydrochloride (2.6 g, 26.9 mmol) and N-methylmorpholine (3 mL, 26.9 mmol). Stir the reaction at 0° C. for 15 minutes and then room temperature for 17 hours. Dilute the reaction with methylene chloride and wash sequentially with water (1×50 mL), 10% aqueous citric acid (1×50 mL), brine (1×50 mL), saturated aqueous sodium bicarbonate (1×50 mL), and brine (1×50 mL). Dry the resulting organic solution with Na2SO4, filter, and purify by flash column chromatography (Silica Gel, 20% acetone/hexanes) to provide the title compound 0.97 g (18% from 2-fluoro-5-methylpyridine) as a clear, yellow oil.

1. customthe reaction at 0° C. for 15 minutes
2. additionDilute
3. washwash sequentially with water (1×50 mL), 10% aqueous citric acid (1×50 mL), brine (1×50 mL), saturated aqueous sodium bicarbonate (1×50 mL), and brine (1×50 mL)
4. dry with materialDry the resulting organic solution with Na2SO4
5. filtrationfilter
6. custompurify by flash column chromatography (Silica Gel, 20% acetone/hexanes)