Reaktion #4982

Reaktionsgleichung

2', 3'-dideoxycytidine

Iodine

→

iodide

Ausbeute 83.0%

5-iodo-2', 3'-dideoxycytidine

Ausbeute 83.0%

Lösungsmittel

methanol

methanol

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONthe free base form of AG3 X4A resin (20 mL, 38 meq, Bio-Rad) was added
2. 2
   Sonstigehydrogen sulfide was bubbled into the reaction for 15 minutes
3. 3
   SonstigeComplete precipitation of mercury(II)
4. 4
   FiltrationThe reaction was filtered
5. 5
   Filtrationthrough filter aid
6. 6
   Waschenthe filter aid was washed with 1:1 methanol-dichloromethane
7. 7
   SonstigeThe filtrate was evaporated onto silica gel (10 g)
8. 8
   WaschenElution

Vorschrift

A solution of 2', 3'-dideoxycytidine (2.11 g, 10 mmol, Raylo) and mercuric acetate (3.35 g, 10.5 mmol, Fisher) in 50 mL of methanol was refluxed for 19 hours. The resulting white suspension was diluted with methanol (50 mL) and dichloromethane (100 mL). Iodine (3.05 g, 12 mmol) was added and the suspension was stirred at 25°. After 4 hours, the free base form of AG3 X4A resin (20 mL, 38 meq, Bio-Rad) was added and hydrogen sulfide was bubbled into the reaction for 15 minutes. Complete precipitation of mercury(II) was verified by TLC. The reaction was filtered through filter aid and the filter aid was washed with 1:1 methanol-dichloromethane. The filtrate was evaporated onto silica gel (10 g) and the loaded siliva gel was placed on top of a 150 g silica gel column. Elution was 5%, 10%, and 20% methanol in dichloromethane afforded 2.79 g (83%) of iodide 19 as a colorless crystalline solid. Two recrystallizations form boiling water afforded, after vacuum-drying at 50°, large, analytically-pure prisms (mp: d 178° ).

Quelle