反应详情

A solution of HCHO (20% aqueous, 1 ml) was added dropwise to a stirred solution of 3'-O-amino-5'-O-(t-butyldimethylsilyl)thymidine (3, 7.42 g, 20 mmol) in dry MeOH (400 ml) at room temperature. After 6 h, another portion of HCHO (20% aqueous, 1.5 ml) was added and stirring continued for 16 h. The resulting solution was evaporated under reduced pressure, and the residue was purified by chromatography on silica gel to give compound 10 (7.25 g, 95%) as clear foam. 1H NMR (CDCl3) δ0.1 [s, 3, (CH3)2 ], 0.9 [s, 9, (CH3)3 ], 1.9 (s, 3, CH3), 2.25-2.72 (m, 2, 2' CH2), 3.85-4.15 (2m, 3, 5' CH2, 4' H), 4.85 (m, 1, 3'H), 6.25 (dd, 1, 1'H), 6.5 and 6.95 (2d, 2, N=CH2), 7.43 (s, 1, (6H), 9.2 (br s, 1 NH).

1. waitcontinued for 16 h
2. customThe resulting solution was evaporated under reduced pressure
3. customthe residue was purified by chromatography on silica gel