Benzenesulfonyl chloride → 1-(Benzenesulfonyl)-2-(2,6-difluorophenyl)benzimidazole

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Reaction Steps

2-(2,6-difluorophenyl)benzimidazole (Example 12) (0.31 g, 1.34 mmol) dissolved in THF (5 mL) was added to NaH (0.10 g, 190 M%). After 5 min, benzenesulfonyl chloride (0.25 mL, 0.35 g, 2.00 mmol, 150 M%) was added. After stirring for 2 h, the reaction was dissolved in ethylacetate, and washed with NaHCO3 (sat. aq.) and NaCl (sat. aq.). The combined washings were dried (Na2SO4), filtered, and concentrated. The product was purified by flash chromatography eluting with 2% MeOH/CH2Cl2 and then recrystallized from diethylether/hexane (3:1), to yield white powders of 1-benzenesulfonyl-2-(2,6-difluorophenyl)benzimidazole (0.41 g, (1.10 mmol, 83% yield). M.p. 104-106° C. 1H-NMR (300 MHz, CD2Cl2): δ8.09 (m, 1H, PhSO2), 7.77 (m, 1H, PhSO2), 7.69 (m, 2H, PhSO2), 7.66-7.53 (m, 2H, H4,7), 7.51-7.39 (m, 4H, PhSO2, H3,5), 7.07 (m, 2H, H3′,5′).

Provenance & Evidence