Reaktion #3746

Reaktionsgleichung

methanol

Triethylamine

thymidine

4,4'-dimethoxytrityl chloride

→

5

Ausbeute 85.3%

5'-O-(4,4'-dimethoxytrityl) thymidine

Ausbeute 85.3%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe solution was stirred at room temperature for 2 hours
2. 2
   workup.ADDITIONwas added
3. 3
   Sonstigeto consume the excess DMTrCl
4. 4
   workup.STIRRINGThe mixture was stirred for 5 minutes
5. 5
   Sonstigethe solvent removed by rotary evaporation
6. 6
   workup.DISSOLUTIONThe residue was dissolved in 250 ml of ethyl acetate
7. 7
   Waschenthe solution was washed with saturated NaHCO3
8. 8
   Trocknendried over MgSO4
9. 9
   SonstigeThe solid was recrystallized from ethyl acetate/hexane

Vorschrift

Triethylamine (10 ml) in 200 ml THF was injected into a solid mixture of 6.8 g (28.0 mmol) thymidine and 10.2 g (28.6 mmol) 4,4'-dimethoxytrityl chloride under nitrogen with stirring. The solution was stirred at room temperature for 2 hours. After completion of the reaction, 10 ml methanol was added to consume the excess DMTrCl. The mixture was stirred for 5 minutes and the solvent removed by rotary evaporation. The residue was dissolved in 250 ml of ethyl acetate and the solution was washed with saturated NaHCO3 and dried over MgSO4. The solid was recrystallized from ethyl acetate/hexane to obtain 13.0 g 5'-protected thymidine 16 (85.6%).: m.p. 124°-126° C.; 1H NMR (200 MHz, CDCl3) δ8.97 (s, 1H, NH), 7.60 (m, 1H, H-6), 6.72-7.42 (m, 13H, Ph), 6.42 (m, 1H, H-1'), 4.56 (m, 1H, H-3'), 4.05 (m, 1H, H-4'), 3.78 (s, 6H, OMe2), 3.41 (m, 2H, H-5'), 2.62 (m, 1H, OH), 2.46 (m, 2H, H-2'), 1.46 (s, 3H, Me); 13C NMR (50 MHz, CDCl3) δ163.0 (C-4), 157.6, 149.8 (C-2), 143.5, 135.0 (C-6), 134.7, 134.6, 129.4, 127.4, 127.3, 126.5, 112.8, 110.9 (C-5), 86.7 (C-4'), 86.2, 84.7 (C-1'), 72.5 (C-3'), 63.8 (C-5'), 55.5 (OCH3), 41.3 (C-2'), 12.5 (CH3).

Quelle