反応 #79182

反応方程式

2-fluoropyridine

2-methyl-1H-benzimidazole

sodium hydride

→

titled compound

収率 71.3%

2-Methyl-1-(2-pyridyl)-1H-benzimidazole

収率 71.3%

溶媒

dimethylacetamide

dimethylacetamide

dimethylacetamide

反応条件

後処理

1. 1
   温度to reflux for about 4 h
2. 2
   その他Volatiles were removed by evaporation under reduced pressure
3. 3
   workup.DISSOLUTIONThe residue was dissolved into ethyl acetate (200 ml)
4. 4
   洗浄washed consecutively with water (3×100 ml) and brine (100 ml)
5. 5
   乾燥The organic layer was dried (magnesium sulfate)
6. 6
   濃縮concentrated to dryness
7. 7
   その他Purification by column chromatography (silica gel, 300 g; n-hexane/ethyl acetate (17/3))

実験手順

To a stirred solution of 2-methyl-1H-benzimidazole (6.61 g, 50 mmol) in dimethylacetamide (40 ml) at room temperature under a nitrogen atmosphere was added sodium hydride (2.40 g, 60 mmol) in portions during 15 min. At the point where the reaction mixture was too viscous to stir, the reaction was diluted with 100 ml of dimethylacetamide. After 50 min., a solution of 2-fluoropyridine (5.83 g, 60 mmol) in dimethylacetamide (30 ml) was added during 15 min. The resulting mixture was heated at 100° C. for 2 h and then to reflux for about 4 h. Volatiles were removed by evaporation under reduced pressure. The residue was dissolved into ethyl acetate (200 ml) and washed consecutively with water (3×100 ml) and brine (100 ml). The organic layer was dried (magnesium sulfate) and concentrated to dryness. Purification by column chromatography (silica gel, 300 g; n-hexane/ethyl acetate (17/3)) yielded 7.46 g (71%) of the titled compound as a light yellow liquid. 1H-NMR (CDCl3) δ: 8.72-8.67 (1H, m), 7.95 (1H, ddd, J=7.7, 7.7, 1.8 Hz), 7.78-7.74 (1H, m), 7.49-7.36 (3H, m), 7.32-7.20 (2H, m), 2.69 (3H, s).

出典