反应详情

To a solution of 0.6730 g (5.02 mmol) 32 in 20 mL glacial acetic acid was added 1.0701 g (6.01 mmol) N-bromosuccinimide. After 16 h at 65° C., the reaction mixture was cooled to room temperature and poured onto 50 mL ice water. This was brought to pH 11 with K2CO3 and extracted with 4×100 mL CHCl3. The combined CHCl3 extracts were washed with 100 mL brine, dried over Na2SO4, filtered and concentrated in vacuo. Purification by flash chromatography (50×115 mm silica gel, linear gradient 2-5% (10% NH4H:MeOH):CH2Cl2) yielded 33. 1H NMR (CDCl3, 400 MHz) δ 8.175 (s, 1H, ArH); 7.877 (s, 1H, ArH); 3.458-3.423 (m, 2H, CH2); 2.725 (t, 2H, J=6.26 Hz, CH2); 1.970-1.911 (m, 2H, CH2); MS (Electrospray): m/z 212.9, 214.8 (M+H, 79Br, 81Br).

1. extractionextracted with 4×100 mL CHCl3
2. washThe combined CHCl3 extracts were washed with 100 mL brine
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customPurification by flash chromatography (50×115 mm silica gel, linear gradient 2-5% (10% NH4H:MeOH):CH2Cl2)