反应详情

To a suspension of the product of step b (1.73 g, 4.62 mmol) in ethanol (25 ml) was added the solution of sodium hydroxide (1.29 g, 32.3 mmol) in water (5 ml). The reaction mixture was heated under reflux for 48 h, allowed to cool to room temperature and concentrated under reduced pressure. The aqueous solution was diluted with water (30 ml) and acidified to pH=2 with 1M hydrochloric acid. The precipitate was collected by filtration, washed with water, and dried to afford the product as an off-white solid (1.53 g, 96%). 1H NMR (300 MHz, d6-DMSO) 8.77 (1H, s), 8.24-7.98 (4H, m), 7.64 (2H, m), 2.91 and 2.64 (2H, 2×d), 2.03 (1H, m), 1.69-1.24 (12H, m).

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 48 h
3. concentrationconcentrated under reduced pressure
4. additionThe aqueous solution was diluted with water (30 ml)
5. filtrationThe precipitate was collected by filtration
6. washwashed with water
7. customdried