Imidazole → 5'-O-tert-Butyldimethylsilylthymidine

Reaction equation

[C@@H:1]1([N:9]2[CH:17]=[C:15]([CH3:16])[C:13](=[O:14])[NH:12][C:10]2=[O:11])[O:8][C@H:5]([CH2:6][OH:7])[C@@H:3]([OH:4])[CH2:2]1.N1C=CN=C1.[C:23]([Si:27](Cl)([CH3:29])[CH3:28])([CH3:26])([CH3:25])[CH3:24]>CN(C=O)C>[Si:27]([O:7][CH2:6][C@H:5]1[O:8][C@@H:1]([N:9]2[CH:17]=[C:15]([CH3:16])[C:13](=[O:14])[NH:12][C:10]2=[O:11])[CH2:2][C@@H:3]1[OH:4])([C:23]([CH3:26])([CH3:25])[CH3:24])([CH3:29])[CH3:28]

Participants

Procedure

To a solution of 2.42 g (10 mmol) thymidine in 15 ml DMF was added 1.7 g (25 mmol) imidazole and 1.6 g (10.6 mmol) tert-butyldimethyl silyl chloride. The solution was stirred at room temperature for 3 hours. DMF was then removed in vacuo and the residue was dissolved in 150 ml of ethyl acetate. The solution was washed with water and the organic layer was dried over MgSO4. After removing the solvent, the solid was recrystallized with ethyl acetate/pentane to obtain 2.5 g pure 5'-O-(tert-butyldimethylsilyl) thymidine 1 (70% yield).: m.p. 193°-194° C.; 1H NMR (500 MHz, CDCl3) δ9.0 (s, 1H, NH), 7.50 (s, 1H, H-6), 6.36 (dd, J=5.8, 8.1 Hz, 1H, H-1'), 4.44 (m, 1H, H-3'), 4.03 (m, 1H, H-4'), 3.85 (m, 2H, H-5'), 2.66 (d, J=3.8 Hz, 1H, OH), 2.35 (m, 1H, H-2'), 2.07 (m, 1H, H-2'), 1.89 (s, 3H, C=CMe), 0.89 (s, 9H, CMe3), 0.09 (s, 6H, SiMe2); --NMR (125 MHz, CDCl3) δ163.8 (C-4), 150.4 (C-2), 135.4 (C-6), 110.9 (C-5), 87.2 (C-4'), 85.0 (C-1'), 72.6 (C-3'), 63.6 (C-5'), 41.1 (C-2'), 25.9 (SiCMe3), 18.3 (SiCMe3), 12.5 (C=CMe), -5.4 (SiMe2), -5.5 (SiMe2).