反应详情

To a suspension of 0.319 g (1.0 mmol) of 2,6-dichloro-1-β-D-ribofuranosylbenzimidazole (67) in 10 mL of H2O, was added dropwise a sat. solution of Br2 /H2O at room temperature. After the addition had been completed, stirring was continued for 3 hr. The reaction mixture was filtered and the solid was washed with portions of H2O, and then recrystallized from MeOH to give 0.335 g (78%, as M MeOH) of 95 as white crystalline needles. MP 140°-142° =C. MS (El) m/e 395.9274 (2%, M+ =395.9279). 1H NMR DMSO-d6): δ8.88 (s, 1, 7-H), 8.08 (s, 1, 4-H), 5.89 (d, 1, 1'-H, J1'2' =8.0 Hz), 5.49 (d, 1, 2'-OH, J2'2' OH=6.5 Hz), 5.40 (t, 5'-OH, J5'-5'OH =4.0 Hz), 5.28 (d, 1, 3'-OH, J3'-3'OH =4.5 HZ), 4.42 (m, 1, 2'-H, J2'-3' =5.5 Hz), 4.13 (1, 3'-H), J3'-4' =1.5 Hz); 4.01 (m, 1, 4'-H, J4'-5" =J4'-5" =2.5 Hz), 3.70 (m, 2, 5'-H and 5"-H, J5'-5" =12.0 Hz). Anal. Calcd. for C12H11BrCl2N2O4MeOH: C, 36.30; H, 3.51; N, 6.51. Found: C, 35.98; H, 3.60; N, 6.39.

1. additionAfter the addition
2. filtrationThe reaction mixture was filtered
3. washthe solid was washed with portions of H2O
4. customrecrystallized from MeOH