反应详情

A 4.69 g (27 mmol) sample of 5-bromo-2-picoline from step 1 was dissolved in 250 mL of carbon tetrachloride, treated with 4.85 g (27 mmol) of N-bromosuccinimide (NBS) and 400 mg (2.4 mmol) of azobisisobutyronitrile (AIBN), and stirred at reflux for 3 h. Filtration and concentration in vacuo provided crude 5-bromo-2-bromomethylpyridine which was 64% monobrominated by NMR; no purification was attempted: NMR (CDCl3) δ4.50 (s, 2H), 7.34 (d, J=8 Hz, 1H), 7.82 (dd, J=8 and 2 Hz, 1H), 8.63 (d, J=2 Hz, 1H).

1. temperatureat reflux for 3 h
2. filtrationFiltration and concentration in vacuo