反应详情

To a cold (−20° C.) suspension of 10 (2.56 g, 10 mmol) and NBS (7.12 g, 40 mmol) in dry acetonitrile (20 mL), hexamethylphosphorous triamide (HT) (6.53 g, 40 mmol) was added dropwise. After addition, the cold bath was removed and the reaction mixture stirred at room temperature for 0.5 h. LiBr (3.44 g, 40 mmol) was added and the mixture was heated at 70° C. for 5 h. The mixture was evaporated under reduced pressure. The dark oil was purified by column chromatography (Silica Gel, 100 Mesh) using CHCl3 as the eluant, to afford the pure product 11 (1.40 g, 44%) as a white solid: mp 146-147° C. 1H NMR: δ 3.46-3.53 (br s, 1H, OH, disappears with D2O), 4.57-4.79 (m, 2H, CH2N), 5.18-5.29 (m, 1H, CHO), 7.30-7.52 (m, 5H Ar), 8.01 (s, 1H, H-3), 8.48 (s, 1H, H-6). IR cm−1: 3240-2500 (OH). Anal. (C13H11N4OBr) C, H, N.

1. additionwas added dropwise
2. additionAfter addition
3. customthe cold bath was removed
4. temperaturethe mixture was heated at 70° C. for 5 h
5. customThe mixture was evaporated under reduced pressure
6. customThe dark oil was purified by column chromatography (Silica Gel, 100 Mesh)