Hydrochloric Acid → 1-(5-Fluoropyridin-2-yl)ethan-1-one

Participants

Reaction Steps

2-Bromo-5-fluoropyridine (13.0 g, 73.9 mmol), copper(I) iodide (2.10 g, 11.1 mmol) and dichlorobis (triphenylphosphine) palladium(II) in anhydrous acetonitrile (100 ml) was added tributyl(1-ethoxyvinyl)atannane (27.5 ml, 81.3 mmol). The reaction was heated at reflux. After heating for 70 hours, 1.5 M aqueous HCl (20 ml) was added to quench the reaction and the mixture was heated at reflux for 1 hour. After cooling to room temperature, the reaction mixture was neutralized with saturated sodium bicarbonate and extracted with ether (3×100 ml). The combined organic layers were dried over dried over sodium sulfate, and concentrated. After removal of solvent, the resulted residue was purified by column chromatography (hexane-ether=5:1) to give the title compound as a clear oil [11.3 g (75% pure), 82%]. 1H NMR (400 MHz, CDCl3) 8.51 (d, J=3.2 Hz, 1H), 8.11 (dd, J=4.4 and 4.4 Hz, 1H), 7.51 (ddd, J=2.8, 3.2 and 2.8 Hz, 1H), 2.71 (s, 3H).

Provenance & Evidence