1,2-Dibromoethane → tert-Butyl (3-bromopyridin-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

2-t-Butoxycarbonylaminopyridine (10 g, 51.5 mmol) was dissolved in tetrahydrofuran (80 mL), and cooled to -78° C. N-butyllithium (120 mmol, 80 mL of 1.49M in hexanes) was added dropwise over a period of 1 h After stirring for an additional 15 min at -78° C. and then for 2.5 h at -10° C., the solution was recooled back down to -78° C. and 1,2-dibromoethane (77.2 mmol, 6.65 mL) was added dropwise over a period of 15 min via syringe. The solution was allowed to warm to room temperature. The reaction was quenched with 100 mL of saturated ammonium chloride and was extracted with ethyl acetate (3×). The organic layers were collected, dried over magnesium sulfate, filtered, and concentrated. The resulting solid was purified by flash chromatography on silica gel (25% ethyl acetate/hexanes) giving 4.5 g (32%) of the titled product as a light brown solid: mp 120°-121° C.; IR (KBr, cm-1) 3191, 2980, 1729, 1521, 1442, 1365, 1272, 1166, 1032; 1H NMR (300 MHZ, DMSO-d6) δ 9.28 (s, 1H), 8.34 (m, 1H), 8.05 (m, 1H), 7.15 (m, 1H), 1.39 (s, 9H); MS (FD) m/e 272 (M+), 274 (M+2); UV (EtOH) 280 nm (ε=4047), 230 nm (ε=9067), 204 nm (ε=16385).

Provenance & Evidence