反应详情

温度

0 °C

5,6-Dichloro-1-(2,5-dideoxy-2-fluoro-beta-D-ribofuranosyl)-1H-benzimidazole (0.45 g, 1.5 mmoles) was dissolved in pyridine (Aldrich, Sure Seal, 20 mL) and boiled to remove water. The solution was chilled to 0° C. in an ice bath. Acetic anhydride (Aldrich, 260 μL, 2.9 mmoles, 2 eq.) was added and the reaction was allowed to warm to room temperature while stirring overnight. Methanol (3 mL) was added and the solvents removed in vacuo. Residual pyridine was removed by coevaporation with toluene (3×). The residue was partitioned between water and ethyl acetate. The ethyl acetate solution was dried with MgSO4, filtered, and the solvent removed in vacuo. The product was used without further purification. The yield was 0.45 g, 88%. MS (FAB+): m/z, 347; 1H NMR (DMSO-d6) δ8.61 (s,1H, H-2), 8.08 (s,1H, Ar—H), 8.00 (s,1H, Ar—H), 6.38 (d, 1H, H-1′, J=18 Hz), 5.70 (d, 1H, H-2′, J=53 Hz), 5.1 (m, 1H), 4.2 (m, 1H), 2.1 (s, 3H, acetyl), 1.38 (d, 3H, H-5′, J=6 Hz).

1. customto remove water
2. temperatureto warm to room temperature
3. customthe solvents removed in vacuo
4. customResidual pyridine was removed by coevaporation with toluene (3×)
5. customThe residue was partitioned between water and ethyl acetate
6. dry with materialThe ethyl acetate solution was dried with MgSO4
7. filtrationfiltered
8. customthe solvent removed in vacuo
9. customThe product was used without further purification