Trimethylsilyl triflate → 2-Bromo4,5,6-trichloro-1-(2,3-di-O-acetyl-5-deoxy-beta-D-ribofuranosyl)-1H-benzimidazole

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Reaction Conditions

Reaction Steps

2-Bromo4,5,6-trichloro-1H-benzimidazole (0.3 g, 1 mmol), acetonitrile (10 mL), and N,O-bis(trimethylsilyl)acetamide were stirred at 70° C. for 15 min., giving a homogeneous solution. To the solution was then added 1,2,3-tri-O-acetyl-5-deoxyribofuranose (0.31 g, 1.2 mmol) in acetonitrile (5 mL) and trimethylsilyltrifluoromethane sulfonate (0.25 mL, 1.3 mmol). The resulting mixture was allowed to stir at 70° C. for 20 min. The mixture was then allowed to cool to RT and was diluted with ethyl acetate and was washed with a saturated aqueous NaHCO3 solution, dried over NaSO4 and the solvents were removed by rotary evaporation. The product was purified by flash chromatography using chloroform as eluent and then recrystallization from methanol afforded 0.29 g (58%) of the title compound as white crystals; m.p. 160-162° C.; 1H NMR (DMSO-d6) δ: 8.14 (s, 1H), 6.16 (d, 1H), 5.63 (t, 1H), 5.27 (dd, 1H), 4.26 (m, 1H), 2.13 (s, 3H), 2.02 (s, 3H), 1.51 (d, 3H).

Provenance & Evidence