反应详情

5-Bromo-3-methylpicolinonitrile (50, 35 g, 0.18 mol) was added to a solution of sodium methoxide (18 g, 0.54 mol) in methanol (200 mL), and the mixture was heated at reflux for 12 h. The solution was cooled to room temperature and concentrated to one third of its volume. The concentrated solution was diluted with water (150 mL), and the products were extracted with chloroform (3×50 mL). The combined extracts were washed with water (2×50 mL), brine (50 mL), dried with sodium sulfate and filtered through a pad of silica gel, washing with chloroform, to produce 51 as an off-white solid (21 g, 79%): mp 80-81° C. IR (film) 2225, 1645, 1589 cm−1; 1H NMR (300 MHz, CDCl3) δ 8.06 (d, J=2.6 Hz, 1H), 7.03 (d, J=2.4 Hz, 1H), 3.83 (s, 3H), 2.43 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 157.65, 139.99, 137.68, 125.05, 120.52, 116.76, 55.84, 18.71; EIMS m/z (rel intensity): 148 (M+, 100); CIMS m/z (rel intensity): 149 (MH+, 100).

1. temperaturethe mixture was heated
2. temperatureat reflux for 12 h
3. concentrationconcentrated to one third of its volume
4. additionThe concentrated solution was diluted with water (150 mL)
5. extractionthe products were extracted with chloroform (3×50 mL)
6. washThe combined extracts were washed with water (2×50 mL), brine (50 mL)
7. dry with materialdried with sodium sulfate
8. filtrationfiltered through a pad of silica gel
9. washwashing with chloroform