反应详情

To a solution of 120 mg (5.16 mmol) of 6-chloro-5,7-difluoro-1,4-dihydroquinoxaline-2,3-dione in 1 mL of H2SO4 (97%) kept in ice bath was added portionwise 60 mg (0.59 mmol) of KNO3. The solution was stirred at room temperature for 14 h and 60 mg of KNO3 was added and it was stirred at room temperature for 24 h. It was diluted by ice-water (4 mL) and the mixture was filtered and washed by water, and dried to leave a yellow solid (94 mg, 65%). The solid was purified by NaOH/HCl precipitate to leave 63 mg of yellow solid, mp>250° C. 1H NMR (DMSO-d6), 12.11 (mb, 1), 12.503 (s, 1).

1. stirringit was stirred at room temperature for 24 h
2. filtrationthe mixture was filtered
3. washwashed by water
4. customdried