Potassium Carbonate → 3-Ethynyl-5-fluoro-4-methylpyridine

Temperature

70 °C

To a solution of 2-(6-chloro-5-fluoro-4-methyl-3-pyridyl)ethynyl-trimethyl-silane (2300 mg, 9.5 mmol) in AcOH (12 mL) was added zinc (1200 mg, 19 mmol). The mixture was heated at 70° C. for 1 hour. The reaction mixture was diluted with ethyl acetate (50 mL), filtered over Celite, evaporated in vacuo and then re-dissolved in ethyl acetate (50 mL) and washed with saturated aqueous sodium bicarbonate solution (20 mL). The organic layer was separated, dried over sodium sulfate, filtered and concentrated in vacuo to provide a residue that was dissolved in MeOH (15 mL) and treated with potassium carbonate (270 mg, 1.9 mmol). The reaction mixture was stirred for 15 minutes at room temperature and then diluted with dichloromethane (50 mL), filtered over Celite, and concentrated in vacuo to provide a residue that was purified by flash chromatography (40 g, Silica, 0-50% diethyl ether in pentane). Desired fractions were combined and evaporated in vacuo to afford the title compound as colorless, crystalline solid (1005 mg, 82%). 1H NMR (400 MHz, CDCl3) δ 8.46 (s, 1H), 8.33 (s, 1H), 3.42 (s, 1H), 2.40 (s, 3H).

1. filtrationfiltered over Celite
2. customevaporated in vacuo
3. dissolutionre-dissolved in ethyl acetate (50 mL)
4. washwashed with saturated aqueous sodium bicarbonate solution (20 mL)
5. customThe organic layer was separated
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto provide a residue that
10. filtrationfiltered over Celite
11. concentrationconcentrated in vacuo
12. customto provide a residue that
13. customwas purified by flash chromatography (40 g, Silica, 0-50% diethyl ether in pentane)
14. customevaporated in vacuo

ORD record

ord-e283ef02694b445bacd8d01d6ffdff0a

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08623889B2