反应详情

温度

50 °C

A solution of the product of Step 8 (1.0 g, 3.6 mmol) in dry dimethylformamide (10 ml) was treated with freshly recrystallised N-bromosuccinimide (1.42 g, 8.0 mmol) and heated at 50° C. for 1 hour. After cooling to room temperature, the reaction mixture was poured into saturated aqueous sodium hydrogen carbonate solution, extracted into dichloromethane, washed twice with brine, dried (MgSO4) and concentrated in vacuo. The residue was chromatographed on silica gel eluting with ethyl acetate to afford the title compound (0.2 g, 16%); 1H NMR (CDCl3) 8.52 (2H, d, J 8 Hz), 7.80 (1H, d, J 11 Hz), 7.49 (1H, s), 7.38 (1H, d, J 8 Hz), 7.32 (2H, d, J 8 Hz), 6.54 (1H, s), 3.17 (2H, t, J 5 Hz), 2.75 (2H, t, 5 Hz).

1. temperatureAfter cooling to room temperature
2. extractionextracted into dichloromethane
3. washwashed twice with brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated in vacuo
6. customThe residue was chromatographed on silica gel eluting with ethyl acetate