Реакция #4982

Уравнение реакции

2', 3'-dideoxycytidine

Iodine

→

iodide

Выход 83.0%

5-iodo-2', 3'-dideoxycytidine

Выход 83.0%

Растворители

methanol

methanol

dichloromethane

Условия реакции

Обработка

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

Методика

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° ).

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