反应详情

温度

80 °C

7-Methyl-5-nitro-1-benzofuran (2.1 g, 12 mmol; Intermediate 63) was dissolved in CCl4 and heated to 80° C. Benzoyl peroxide (0.43 g, 1.6 mmol) was added followed by NBS (2.1 g, 12 mmol) that was added in small portions. The reaction mixture was heated at reflux overnight with stirring. Additional benzoyl peroxide (0.08 mmol) and NBS (0.2 mmol) were added and the reaction mixture was stirred for one additional night. After this time, the mixture was filtered and concentrated. The crude was redissolved in DCM and washed with water. The organic solvent was dried (MgSO4) and evaporated. The residue was purified using preparative HPLC with a gradient of 45-70% MeCN. This afforded 0.7 g (22%) of 7-(bromomethyl)-5-nitro-benzofuran as a solid. 1H NMR (400 MHz, CDCl3) δ ppm 4.78 (s, 2H) 6.96 (d, J=2.3 Hz, 1H) 7.84 (d, J=2.3 Hz, 1H) 8.28 (d, J=2.3 Hz, 1H) 8.49 (d, J=2.3 Hz, 1H). HPLC Rt=1.9 min (System A; 30-80% MeCN over 3 min ACE column).

1. additionwas added in small portions
2. temperatureThe reaction mixture was heated
3. temperatureat reflux overnight
4. stirringthe reaction mixture was stirred for one additional night
5. filtrationAfter this time, the mixture was filtered
6. concentrationconcentrated
7. dissolutionThe crude was redissolved in DCM
8. washwashed with water
9. dry with materialThe organic solvent was dried (MgSO4)
10. customevaporated
11. customThe residue was purified