反应详情

温度

0 °C

A solution of sodium iodide (3.6 g) and chlorotrimethylsilane (794 ml) in dry acetonitrile (15 ml) was stirred with molecular sieves 4A (200 mg) at 0° C. for 5 minutes (colorless sodium chloride deposited during stirring). 1,2,3-Tri-O-acetyl-5-deoxy-β-D-ribofuranose (2.0 g) was added and the mixture was stirred at 0° C. for 30 min. Then, a solution of the trimethylsilylated 5-fluorocytosine, freshly prepared from 5-fluorocytosine (1.12 g), in dry acetonitrile (5 ml) was added at 0° C. and stirring was continued for 3 h at room temperature. The mixture was filtered, the filtrate was concentrated in vacuo, and the residue was partitioned between dichloromethane and saturated aq. sodium bicarbonate solution. The aqueous layer was extracted with CH2Cl2 /MeOH (10:1). The combined organic layers were dried over anhydrous sodium sulfate and evaporated under reduced pressure. The residue was purified by silica gel chromatography using CH2Cl2 /MeOH (15:1) as an eluent, followed by recrystallization from isopropanol to give 1.24 g of 2',3'-di-O-acetyl-5'-deoxy-5-fluorocytidine.

1. additionwas added at 0° C.
2. stirringstirring
3. waitwas continued for 3 h at room temperature
4. filtrationThe mixture was filtered
5. concentrationthe filtrate was concentrated in vacuo
6. customthe residue was partitioned between dichloromethane and saturated aq. sodium bicarbonate solution
7. extractionThe aqueous layer was extracted with CH2Cl2 /MeOH (10:1)
8. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
9. customevaporated under reduced pressure
10. customThe residue was purified by silica gel chromatography
11. customfollowed by recrystallization from isopropanol