2,5-Dibromopyridine → 5-Bromo-2-(4-fluorophenyl)pyridine

Participants

Reaction Steps

To a degassed mixture of 2,5-dibromopyridine (500 mg, 2.11 mmol) and 4-fluorobenzeneboronic acid (444 mg, 3.17 mmol) in ethylene glycol dimethyl ether (4.2 ml) and 2M aqueous sodium carbonate (2.1 ml) was added tetrakis(triphenylphosphine)palladium(0) (98 mg, 0.08 mmol). This mixture was heated at reflux for 14 h. After cooling the crude reaction was partitioned between water and dichloromethane. The organics were dried over anhydrous magnesium sulfate, filtered and adsorbed onto silica. Purification by chromatography on silica gel, eluting with a mixture of 4% diethyl ether in isohexane, gave 5-bromo-2-(4-fluorophenyl)pyridine (470 mg) as a white solid: δH (360 MHz, CDCl3) 7.30 (1H, d, J 7), 7.12-7.19 (2H, m), 7.57 (1H, d, J 8), 7.86 (1H, dd, J 2 and 8), 7.92-7.98 (2H, m), 8.72 (1H, d, J 2), m/z (ES+) 251, 252, 253, 254 (M++H).

Provenance & Evidence