反应详情

To a solution of 2-acetyl-7-methoxybenzofuran (4.0 g) in acetic anhydride (50 mL) at 0° C. was added 70% nitric acid (1.5 mL) drop-wise. The mixture was warmed to room temperature and stirred for 3 h then poured into ice-cold saturated sodium carbonate (200 mL). Solid sodium carbonate was added carefully with stirring until basic (pH=8). The mixture was filtered and the solid collected by vacuum filtration. The solid was boiled in 100 mL (methanol) for 1 h, then cooled to 0° C. and filtered to give 2-acetyl-7-methoxy-4-nitrobenzpfuran (2.1 g). 1H NMR (300 MHz) δ 8.29 (d,J=8.9 Hz, 1H), 8.14 (s,1H), 7.00 (d,J=8.9 Hz, 1H), 4.14 (s,3H), 2.68 (s, 3H).

1. stirringwith stirring until basic (pH=8)
2. filtrationThe mixture was filtered
3. filtrationthe solid collected by vacuum filtration
4. waitThe solid was boiled in 100 mL (methanol) for 1 h
5. temperaturecooled to 0° C.
6. filtrationfiltered
7. customto give 2-acetyl-7-methoxy-4-nitrobenzpfuran (2.1 g)