反应详情

4-Bromothiophene-2-carboxylic acid (1.75 g, 8.5 mmol) was dissolved in 40 mL of t-BuOH. To this solution diphenylphosphoryl azide (2.8 g, 10.2 mmol) and triethylamine (1.4 mL, 10.1 mmol) were added. The reaction mixture was heated to reflux for 5 hours, cooled room temperature, and diluted with EtOAc. The organic layer was washed with 10% citric acid, saturated sodium bicarbonate and brine, and concentrated to an oil, which was purified by column chromatography on silica (0 to 25% EtOAc/hexanes) to give the product, 1.3 g, 4.7 mmol, 55%. 1H NMR 500 MHz (CDCl3) 6.96 (1H, br s), 6.83 (1H, s), 6.43 (1H, s), 1.54 (9H, s).

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 5 hours
3. washThe organic layer was washed with 10% citric acid, saturated sodium bicarbonate and brine
4. concentrationconcentrated to an oil, which
5. customwas purified by column chromatography on silica (0 to 25% EtOAc/hexanes)
6. customto give the product, 1.3 g, 4.7 mmol, 55%