Benzenesulfonyl chloride → 1-(Benzenesulfonyl)-2-(2,6-difluorophenyl)benzimidazole
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([F:8])[C:3]=1[C:9]1[NH:10][C:11]2[CH:17]=[CH:16][CH:15]=[CH:14][C:12]=2[N:13]=1.[H-].[Na+].[C:20]1([S:26](Cl)(=[O:28])=[O:27])[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>C1COCC1.C(OC(=O)C)C>[C:20]1([S:26]([N:13]2[C:12]3[CH:14]=[CH:15][CH:16]=[CH:17][C:11]=3[N:10]=[C:9]2[C:3]2[C:4]([F:8])=[CH:5][CH:6]=[CH:7][C:2]=2[F:1])(=[O:28])=[O:27])[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1Participants
Procedure
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): δ 8.09 (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′).
Workup
- washwashed with NaHCO3 (sat. aq.) and NaCl (sat. aq.)
- dry with materialThe combined washings were dried (Na2SO4)
- filtrationfiltered
- concentrationconcentrated
- customThe product was purified by flash chromatography
- washeluting with 2% MeOH/CH2Cl2
- customrecrystallized from diethylether/hexane (3:1)
Sources & evidence
- ORD record
- ord-bb8684bfdd054aa4bd6970fefe6fd9bc
- Source dataset
- uspto-grants-2005_05
- Patent number
- US06894068B2
Reaction notes
Loading…