反应详情

A mixture of 5'-O-phthalimidothymidine (8.54 g, 22 mmol), t-butyldiphenylsilylchloride (6.9 ml), 26.5 mmol), imidazole (3.9 g, 57.3 mmol) and dry DMF (130 ml) was stirred at room temperature for 16 h under argon. The reaction mixture was poured into ice-water (600 ml) and the solution was extracted with CH2Cl2 (2×400 ml). The organic layer was washed with water (2×250 ml) and dried (MgSO4). The CH2Cl2 layer was concentrated to furnish a gummy residue which on purification by silica gel chromatography (eluted with EtOAc:Hexanes; 1:1, v/v) furnished 12.65 g (92%) of 3'-O-(t-butyldiphenylsilyl)-5'-O-phthalimidothymidine as crystalline material (mp 172-173.5° C.). 1H NMR (DMSO-d6) δ 11.31 (s, 1, NH), 7.83 (m, 4, ArH), 7.59 (m, 4, TBDPhH), 7.51 (s, 1, C6H), 7.37-7.45 (m, 6, TBDPhH), 6.30 (dd, 1, H1', J1',2' =8.8 Hz, J1',2" =5.6 Hz), 4.55 (m, 1, H4'), 4.15 (m, 1, H3'), 3.94-4.04 (m, 2, H5',5"), 2.06-2.13 (m, 2, H2',2"), 1.97 (s, 3, CH3), 1.03 (s, 9, C(CH3)3). Anal. Calcd. for C34H35O7N3Si: C, 65.26; H, 5.64; N, 6.71. Found: C, 65.00; H, 5.60; N, 6.42.

1. extractionthe solution was extracted with CH2Cl2 (2×400 ml)
2. washThe organic layer was washed with water (2×250 ml)
3. dry with materialdried (MgSO4)
4. concentrationThe CH2Cl2 layer was concentrated
5. customto furnish a gummy residue which
6. customon purification by silica gel chromatography (
7. washeluted with EtOAc