Reaction #3745

Reaction equation

thymidine

imidazole

tert-butyldimethyl silyl chloride

→

5'-O-(tert-butyldimethylsilyl) thymidine

Yield 70.1%

Solvents

DMF

Conditions

Workup

1. 1
   OtherDMF was then removed in vacuo
2. 2
   workup.DISSOLUTIONthe residue was dissolved in 150 ml of ethyl acetate
3. 3
   WashThe solution was washed with water
4. 4
   Dryingthe organic layer was dried over MgSO4
5. 5
   OtherAfter removing the solvent
6. 6
   Otherthe solid was recrystallized with ethyl acetate/pentane

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).

Source