反应详情

5-Bromo-2-(2-nitrovinylamino)benzoic acid (Compound of step 1, 25 g, 87 mmol) and potassium acetate (10.5 g, 104 mmol) in acetic anhydride (112 mL, 1185 mmol) were stirred for 3 hours at 120° C. The precipitate was filtered, and washed with acetic acid till the filtrate was colorless. It was further washed with water and dried to obtain the title compound. Yield: 15 g (64%); 1H NMR (CDCl3, 500 MHz): δ 9.275 (s, 1H), 8.611-8.615 (d, 1H, J=2 Hz), 8.100-8.118 (d, 1H, J=9 Hz), 8.026-8.048 (dd, 1H, J=8.5 Hz, 2 Hz).

1. filtrationThe precipitate was filtered
2. washwashed with acetic acid till the filtrate
3. washIt was further washed with water
4. customdried