反应详情

500 ml of acetic anhydride and 500 ml of pyridine were added to 45 g of guanosine, and the reaction mixture was stirred for 12 hours at room temperature. The precipitated crystalline was separated by filtration and washed with water. The filtrate was concentrated under reduced pressure, and the precipitated crystalline was obtained by filtration. The first and second crystals were put together to give 2',3',5'-O-triacetylguanosine (yield: 94.4%). (ii) 375 ml of phosphoruos oxychloride and 20 ml of diethylaniline was added to 55 g of 2',3',5'-O-triacetylguanosine, and the reaction mixture was refluxed with heating for 3 minutes. The solution was concentrated to 100 ml under reduced pressure, poured into ice-cold water and extracted with dichloromethane. The dichloromethane layer was washed to be neutralized and dried over sodium sulfate anhydrate. After purification by silica gel column chromatography, the solution was concentrated under reduced pressure to give 40 g of 6-chloro-2-amino-9-(2,3,5-O-triacetyl-β-D-ribofuranosyl)-9H-purine (yield 69%).

1. temperaturethe reaction mixture was refluxed
2. temperaturewith heating for 3 minutes
3. concentrationThe solution was concentrated to 100 ml under reduced pressure
4. additionpoured into ice-cold water
5. extractionextracted with dichloromethane
6. washThe dichloromethane layer was washed
7. dry with materialdried over sodium sulfate anhydrate
8. customAfter purification by silica gel column chromatography
9. concentrationthe solution was concentrated under reduced pressure