Acetic Acid → HCID 493368, compound

Participants

Reaction Steps

Sodium carbonate (0.28 g, 2.65 mmol) and 2-bromo-5,6-dichloro-1-(2,3,5-tri-O-acetyl-beta-L-ribofuranosyl)-1H-benzimidazole (1.39 g, 2.65 mmol) were combined with water (4 mL), methanol (20 mL) and ethanol (20 mL) and stirred at rt for 1.5 h. Acetic acid (0.3 mL, 5.3 mmol) was added and the suspension was concentrated to a solid. Purification of the residue on a silica gel column (2.5×20 cm, 230-400 mesh) with 1:9 ethanol: CH2Cl2 gave 2-bromo-5,6-dichloro-1-beta-L-ribofuranosyl-1H-benzimidazole as a white amorphous solid (0.79 g, 2.0 mmol, 75%); m.p. 169° C.; [a]20D =(+) 105 (c=0.5 DMF); UV lmax (e): pH 7.0: 298 nm (6,700), 289 (6,500), 255 (6,900); 0.1 N NaOH: 298 nm (6,700), 295 (5,400), 256 (6,700); MS (CI): m/z 399 (M+1); 1H NMR (DMSO-d6) d 8.57 (s, 1H, Ar--H), 7.96 (s, 1H, Ar--H), 5.89 (d, J=7.9 Hz, H-1'), 5.48 (d, 1H, OH, J=6.3 Hz), 5.42 (t, 1H, OH, J=4.5 Hz), 5.29 (d, 1H, OH, J=4.2 Hz), 4.43 (apparent dd, 1H, H-2', J=13.3 Hz, J=6.1 Hz), 4.14 (apparent t, 1H, H-3', J=4.3 Hz), 4.01 (apparent d, 1H, H-4', J=1.7 Hz), 3.77-3.63 (m, 2H, H-5').

Provenance & Evidence