2-Chloro-3-methyl-5-nitropyridine → 2-Fluoro-3-methyl-5-nitropyridine

Participants

Reaction Steps

2-Chloro-3-methyl-5-nitropyridine (15 g, 86.9 mmol; from Maybridge Chemical Co.), KF (12 g, 258 mmol) and tetraphenylphosphonium bromide (20 g, 47.7 mmol; Aldrich) were combined in 200 mL of acetonitrile and heated at reflux for 4 days. The mixture was diluted with Et2O (500 mL) and filtered, and the filtrate was concentrated. The residue was triturated with hot hexane (4×200 mL), and the hexane solutions were combined and concentrated to afford the title compound as a solid (8.4 g, 60%): 1H NMR (DMSO-d6, 300 MHz) δ2.42 (s, 3H), 8.43 (m, 1H), 8.95 (dd, J=1.6 Hz, 1H); MS (CI/NH3) m/z: 157 (M+H)+.

Provenance & Evidence