反应详情

A solution cf 6-fluoro-2(3H)-benzoxazolone (1.0 g) in 80% aqueous sulfuric acid (6.5 g) was cooled to 0° to 5° C., and 60% nitric acid (0.8 g) was gradually added thereto at 0° to 5° C. The resultant mixture was stirred at the same temperature for 30 minutes and poured onto ice water. The precipitated crystals were collected by filtration, washed with water and dried to give 6-fluoro-5-nitro-2(3H)-benzoxazolone (1.1 g). m.p., 175.4° C. 1H-NMR (CDCl3 +DMSO-D6) δ ppm: 4.0 (1H, broad), 6.8-7.9 (3H, m).

1. customat 0° to 5° C
2. additionpoured onto ice water
3. filtrationThe precipitated crystals were collected by filtration
4. washwashed with water
5. customdried