反应详情

To a solution of compound 43 (0.08 g, 0.14 mmol) in MeCN (10 mL) was added DMAP (0.02 g, 0.14 mmol) and Et3N (0.07 g, 0.71 mmol) followed by addition of TsCl (0.08 g, 0.43 mmol) and the solution was stirred at room temperature for 1 h. To the solution was added NH4OH (30%, 2 mL) and the mixture was stirred at room temperature for 1 h. Solvent was evaporated to dryness and the residue was co-evaporated with toluene twice to give crude cytosine analog which was dissolved in CH2Cl2 (10 mL) and pyridine (1 mL). To the solution was added BzCl (0.1 mL, 0.86 mmol) and the solution was stirred at room temperature for 2 h. Water (5 mL) was added and the mixture was evaporated to dryness under reduced pressure. The residue was dissolved in EtOAc (100 mL) and the solution was washed with water, brine and dried over Na2SO4. Solvent was evaporated and the residue was purified by silica gel column chromatography (0-60% EtOAc in hexanes) to give N-benzoylcytosine analog which was dissolved in THF (10 mL). To the solution was added TBAF (0.12 g, 0.48 mmol) and the solution was stirred at room temperature for 1 h. Solvent was evaporated and the residue was purified by silica gel column (0-8% MeOH in CH2Cl2) to give N-benzoyl nucleoside which was dissolved in 7N NH3 in MeOH (8 mL) and the solution was stirred at room temperature for 20 h. Solvent was evaporated and the residue was purified by silica gel column (0-30% MeOH in CH2Cl2) to give product 49 (0.09 g, 56% from 43). 1H NMR (400 MHz, CD3OD) δ: 8.09 (d, J=7.6 Hz, 1H), 5.99 (s, 1H), 5.87 (d, J=7.6 Hz, 1H), 3.95 (m, 6H), 2.80 (m, 4H). LC-MS (ESI): 284 [M+H]+.

1. stirringthe mixture was stirred at room temperature for 1 h
2. customSolvent was evaporated to dryness
3. customto give crude cytosine analog which
4. stirringthe solution was stirred at room temperature for 2 h
5. customthe mixture was evaporated to dryness under reduced pressure
6. dissolutionThe residue was dissolved in EtOAc (100 mL)
7. washthe solution was washed with water, brine
8. dry with materialdried over Na2SO4
9. customSolvent was evaporated
10. customthe residue was purified by silica gel column chromatography (0-60% EtOAc in hexanes)