Sodium Carbonate → 2-Bromo-5-(4-fluorophenyl)pyrazine

Participants

Reaction Conditions

Reaction Steps

To a solution of 2,5-dibromopyrazine (100 mg, 0.4 mmol) in toluene (6 mL) and ethanol (3 mL) was added (4-fluorophenyl)boronic acid (29 mg, 0.2 mmol) and 2M sodium carbonate solution (2.84 mL). The solution was purged with argon for 15 min, Pd(PPh3)4 (4 mg, 0.004 mmol) was added, and the reaction mixture was purged with argon for 15 min. The resulting mixture was heated to 40° C. and stirred for 1 h. The reaction mixture was concentrated, diluted with water (20 mL), and extracted with ethyl acetate (2×100 mL). The combined extracts were washed with brine solution (10 mL), and dried over Na2SO4 and concentration in vacuo. The crude product was purified by flash chromatography (60-120μ, 5% ethyl acetate in hexane) to afford 2-bromo-5-(4-fluorophenyl)pyrazine as off-white solid (60 mg, 57% yield). 1H NMR (400 MHz, DMSO-d6): δ 9.08 (s, 1H), 8.88 (s, 1H), 8.18-8.15 (m, 2H), 7.37 (dd, 2H); LC-MS m/z calculated for [M+H]+ 252.97. found 253.0.

Provenance & Evidence