反应详情

To a stirred solution of 12 (10.68 g, 50.7 mmol) in chloroform (500 mL) was added N-bromosuccinamide (45.20 g, 253.9 mmol) and the reaction mixture stirred under an atmosphere of nitrogen and at reflux temperature for 5 h. The reaction mixture was transferred to a separatory funnel and washed with saturated sodium sulfite solution (2×250 mL) followed by brine solution (2×250 mL). The chloroform fraction was dried over anhydrous sodium sulfate and concentrated and the reddish oil was purified by flash chromatography on silica gel using EtOAc/hexane (4:6) for elution. Yield 6.05 g. (41.2%). Mp 119-121° C.; 1H NMR (CDCl3): δ 5.53 (s, 2H, CH2), 7.35-7.39 (m, 5H, Ar—H), 9.03 (s, 1H, purine C8—H), 9.09 (s, 1H, purine C2—H).

1. temperatureat reflux temperature for 5 h
2. customThe reaction mixture was transferred to a separatory funnel
3. washwashed with saturated sodium sulfite solution (2×250 mL)
4. dry with materialThe chloroform fraction was dried over anhydrous sodium sulfate
5. concentrationconcentrated
6. customthe reddish oil was purified by flash chromatography on silica gel
7. washfor elution