反应详情

温度

0 °C

To a stirred solution of (E)-2-styryl-1H-benzimidazole (0.49 g, 2.2 mmol) in dimethylacetamide (20 ml) at 0° C. under a nitrogen atmosphere was added sodium hydride (0.11 g, 2.8 mmol). After stirring at 0° C. for 20 min. and then at room temperature for 30 min., a solution of 2-chloro-3-trifluoromethylpyridine (0.60 g, 3.3 mmol) in dimethylacetamide (5 ml) was added. The resulting mixture was heated to reflux for about 3 h 20 min. After cooling, copper bronze (0.45 g, 7.1 mg-atom) was added and heating was continued for 9 h 20 min. The reaction mixture was filtered through a pad of celite and the filtrate was diluted with dichloromethane (200 ml), washed consecutively with water (3×200 ml) and brine (100 ml), dried (magnesium sulfate) and concentrated to dryness. Purification by column chromatography (silica gel, 150 g; n-hexane/ethyl acetate (2/1)) followed by recrystallization from a mixture of isopropyl ether and n-hexane yielded 37 mg (5%) of the titled compound as white solids.

1. waitat room temperature for 30 min.
2. temperatureThe resulting mixture was heated
3. temperatureto reflux for about 3 h 20 min
4. temperatureAfter cooling
5. temperatureheating
6. waitwas continued for 9 h 20 min
7. filtrationThe reaction mixture was filtered through a pad of celite
8. additionthe filtrate was diluted with dichloromethane (200 ml)
9. washwashed consecutively with water (3×200 ml) and brine (100 ml)
10. dry with materialdried (magnesium sulfate)
11. concentrationconcentrated to dryness
12. customPurification by column chromatography (silica gel, 150 g; n-hexane/ethyl acetate (2/1))
13. customfollowed by recrystallization from a mixture of isopropyl ether and n-hexane