反应详情

To a stirred suspension of 6-bromo-7-chloro-3,4-dihydroquinoxaline-2(1H)-one (0.06 g, 0.23 mmol, as obtained above) in CF3COOH (0.5 mL) was added fuming HNO3 (0.02 mL, 0.46 mmol) and the resulting reddish yellow suspension was stirred at room temperature overnight. The cream colored suspension so obtained was poured into ice (2.5 mL) and the precipitated solid was filtered, washed with water (1.0 mL), and dried under vacuum to afford 0.049 g (70%) of the title compound as a cream colored powder. 1H NMR (DMSO-d6): δ 7.577 (s, 1H), 8.251 (s, 1H), 12.879 (s, 1H). The crude product was used as such for the final reaction.

1. customThe cream colored suspension so obtained
2. filtrationthe precipitated solid was filtered
3. washwashed with water (1.0 mL)
4. customdried under vacuum