反应详情

A solution of ((3aR,4R,6R,6aR)-6-(4-((2,4-dimethoxybenzyl)amino)-7H-pyrrolo[2,3-d]pyrimidin-7-yl)-2,2-dimethyltetrahydrofuro[3,4-d][1,3]dioxol-4-yl)methanol (2.83 g, 6.20 mmol) and triphenylphosphine (2.28 g, 8.68 mmol) in dry tetrahydrofuran (32 mL) was cooled at 0° C. in an ice/water bath. Diisopropyl azodicarboxylate (1.71 mL, 8.68 mmol) was added dropwise, followed by a solution of diphenylphosphonic azide (1.87 mL, 8.68 mmol) in tetrahydrofuran (5.3 mL, 66 mmol). Upon addition of the DPPA solution, a white milky precipitate formed. After about 30 minutes, the reaction mixture was allowed to warm to room temperature and stir overnight. After 24 h, HPLC indicated that all the starting material had been consumed. The reaction mixture was concentrated to about ½ the original volume and purified by flash chromatography (175 g silica gel, 10-55% EA/hept) to yield the title compound (2.49 g, 83%) as a slightly yellow stiff foam: MS (ESI+) for C23H27N7O5 m/z 482.2 (M+H)+; (ESI−) for C23H27N7O5 m/z 480.1 (M+H)−, m/z 526.1 (M+CO2H)−; HPLC purity 97% (ret. time, 3.64 min).

1. customa white milky precipitate formed
2. waitAfter 24 h
3. customhad been consumed
4. concentrationThe reaction mixture was concentrated
5. custompurified by flash chromatography (175 g silica gel, 10-55% EA/hept)