反应详情

To a suspension of magnesium (0.119 g, 4.97 mmol) in THF (3 mL) was added 2-bromothiophene (0.811 g, 4.97 mmol) and the reaction mixture was stirred for 3 h. Another equivalent of 2-bromothiophene (0.811 g, 4.97 mmol) was added and the reaction mixture was heated at the reflux temperature for 2 h, then allowed to cool to room temperature. The resulting mixture was added to a solution of 5-bromo-2-dimethylaminopyridine (1.0 g, 4.97 mmol) in THF (12 mL) and the reaction was heated at the reflux temperature for 11 h, then was allowed to cool to room temperature. The resulting mixture was treated with water (10 mL), extracted with EtOAc (3×30 mL), dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by flash chromatography (10% EtOAc/hex) to give 5-(2-thienyl)-2-dimethylaminopyridine (0.3 g, 29%): TLC (10% EtOAc/hex) Rf 0.24; HPLC ES-MS m/z (relative abundance) 205 (MH+, 100%).

1. temperaturethe reaction mixture was heated at the reflux temperature for 2 h
2. temperaturethe reaction was heated at the reflux temperature for 11 h
3. temperatureto cool to room temperature
4. extractionextracted with EtOAc (3×30 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated under reduced pressure
7. customThe crude product was purified by flash chromatography (10% EtOAc/hex)