Реакция #76831

Уравнение реакции

DCC

butyric acid

(R)-9-[4-(N-tert-Butoxycarbonyl-L-valyloxy)-2-hydroxymethylbutyl]guanine

→

intermediate

Выход 34.4%

(R)-9-[4-(N-tert-Butoxycarbonyl-L-valyloxy)-2-(butyryloxymethyl) butyl]guanine

Выход 34.4%

Растворители

dichloromethane

Условия реакции

Обработка

1. 1
   ФильтрацияAfter 4 hours at room temperature the mixture was filtered
2. 2
   Другоеthe filtrate was evaporated
3. 3
   workup.DISSOLUTIONThe residue was dissolved in pyridine (5 ml)
4. 4
   workup.STIRRINGthe mixture was stirred for an additional 20 hours
5. 5
   ДругоеThe reaction mixture was evaporated
6. 6
   Другоеchromatographed first on silica gel
7. 7
   Промывкаon aluminium oxide, in both cases eluted with dichloromethane/methanol

Методика

DCC (110 mg, 0.53 mmol) was dissolved in dichloromethane (10 ml) and butyric acid (82 mg, 0.93 mmol) was added. After 4 hours at room temperature the mixture was filtered and the filtrate was evaporated. The residue was dissolved in pyridine (5 ml) and (R)-9-[4-(N-tert-Butoxycarbonyl-L-valyloxy)-2-hydroxymethylbutyl]guanine (200 mg, 0.44 mmol) (Example 1, step a) was added. The mixture was stirred for 120 hours at room temperature. According to TLC the reaction was incomplete and more anhydride was made using the procedure above. This anhydride was added and the mixture was stirred for an additional 20 hours. The reaction mixture was evaporated and chromatographed first on silica gel and then on aluminium oxide, in both cases eluted with dichloromethane/methanol to give 79 mg of the intermediate product.

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