反应详情

To 5,6,7-trifluoro-1,4-dihydro-2,3-quinoxalinedione (93 mg, 0.43 mmol) is added concentrated sulfuric acid (0.5 mL). While the flask is an ice bath, KNO3 is slowly added, giving a brown mixture, which is stirred overnight. The reaction mixture, now dark red, is then added into ice water (5 mL), instantly giving an orange precipitate, which is collected by centrifugation. The powder was crystallized from EtOH (5 mL) and dried in vacuo to yield 24 mg (20%) of pale orange microcrystals. 1H NMR (DMSO-d6), 11.9 (br s, 1H), 12.6 (br s, 1H).

1. customgiving a brown mixture, which
2. custominstantly giving an orange precipitate, which
3. customis collected by centrifugation
4. customThe powder was crystallized from EtOH (5 mL)
5. customdried in vacuo
6. customto yield 24 mg (20%) of pale orange microcrystals