反应详情

温度

0 °C

The product from Step (a) (5.00 g, 29.9 mmol, 1 equiv) was dissolved in concentrated H2SO4 (30 mL) and cooled to 0° C. Concentrated HNO3 (2.2 mL) was added slowly via pipet, and the solution gradually became dark brown. After 30 minutes at 0° C., the reaction mixture was poured onto ice (˜200 mL), and the mixture was allowed to stir and warm to room temperature. The solid precipitate was collected by filtration and washed several times with water. The solid was suspended in 6N HCl (30 mL) and the mixture was heated to reflux for 5 hours, then stirred at room temperature for 18 hours. The reaction mixture was diluted with H2O and neutralized with solid K2CO3. The resulting precipitate was collected by filtration and rinsed several times with water, affording 2.82 g (55%) of the title compound as a brown solid. MS (ES+) m/e 171 [M+H].

1. additionthe reaction mixture was poured onto ice (˜200 mL)
2. temperaturewarm to room temperature
3. filtrationThe solid precipitate was collected by filtration
4. washwashed several times with water
5. temperaturethe mixture was heated
6. temperatureto reflux for 5 hours
7. stirringstirred at room temperature for 18 hours
8. additionThe reaction mixture was diluted with H2O and neutralized with solid K2CO3
9. filtrationThe resulting precipitate was collected by filtration
10. washrinsed several times with water