تفاعل #3746

معادلة التفاعل

methanol

Triethylamine

thymidine

4,4'-dimethoxytrityl chloride

→

5

المردود 85.3%

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

المردود 85.3%

المذيبات

THF

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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).

المصدر