反应详情

N2-Phenoxyacetyl-2′-O-(2-cyanoethoxymethyl)guanosine (660 mg, 1.32 mmol) was subjected to azeotropic distillation with pyridine, and then was dried with a vacuum pump for 30 minutes. The residue was dissolved in 9 mL of THF, and 2.1 g of pyridine (26.4 mmol) and 600 mg of molecular sieve 4 A were added under an argon atmosphere, and the reaction solution was stirred for 10 minutes. To the solution was added 540 mg of 4,4′-dimethoxytritylchloride (1.58 mmol) by 3 portions every 1 hour, and the reaction solution was further stirred for 1 hour. After 2 mL of methanol was added and the reaction solution was stirred for 2 minutes, the reaction solution was filtrated with a celite, and was washed with ethyl acetate. After concentrating the filtrate with evaporation, the residue was dissolved in ethyl acetate, and was separated with a saturated aqueous sodium bicarbonate solution. After the organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, the solvent was distilled off. The obtained residue was purified by silica gel chromatography to obtain the objective compound (800 mg, yield 75%).

1. customwas dried with a vacuum pump for 30 minutes
2. dissolutionThe residue was dissolved in 9 mL of THF
3. stirringthe reaction solution was further stirred for 1 hour
4. stirringthe reaction solution was stirred for 2 minutes
5. filtrationthe reaction solution was filtrated with a celite
6. washwas washed with ethyl acetate
7. concentrationAfter concentrating the filtrate
8. customwith evaporation
9. dissolutionthe residue was dissolved in ethyl acetate
10. customwas separated with a saturated aqueous sodium bicarbonate solution
11. washAfter the organic layer was washed with saturated brine
12. dry with materialdried over anhydrous magnesium sulfate
13. distillationthe solvent was distilled off
14. customThe obtained residue was purified by silica gel chromatography