Stannous Chloride → 5-bromo-1-(4-fluorophenyl)-2-methyl-1H-benzimidazole
Reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]([C:12]2[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=2)[C:9](=O)[CH3:10])=[C:4]([N+:19]([O-])=O)[CH:3]=1.[Sn](Cl)Cl>C(O)C>[Br:1][C:2]1[CH:7]=[CH:6][C:5]2[N:8]([C:12]3[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=3)[C:9]([CH3:10])=[N:19][C:4]=2[CH:3]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 90 °C
Procedure
To a stirred room temperature solution of N-(4-bromo-2-nitrophenyl)-N-(4-fluorophenyl)acetamide (3.7 g, 10.8 mmol) in ethanol (75 mL) was added tin (II) chloride (6 g, 31.4 mmol) and the mixture was warmed at 90° C. After 3 hours, the mixture was cooled, concentrated in vacuo, diluted with cold water, made basic with 2 N NaOH (pH 11), and extracted with three 75 mL portions of methylene chloride. The combined organic layers were washed with water, dried over anhydrous sodium sulfate, and concentrated in vacuo to afford a reddish brown oil. The residue was purified by column chromatography over silica gel eluting with 0-50% ethyl acetate in methylene chloride to afford 830 mg of 5-bromo-1-(4-fluorophenyl)-2-methyl-1H-benzimidazole as an off-white solid.
Workup
- temperaturethe mixture was cooled
- concentrationconcentrated in vacuo
- additiondiluted with cold water
- extractionextracted with three 75 mL portions of methylene chloride
- washThe combined organic layers were washed with water
- dry with materialdried over anhydrous sodium sulfate
- concentrationconcentrated in vacuo
- customto afford a reddish brown oil
- customThe residue was purified by column chromatography over silica gel eluting with 0-50% ethyl acetate in methylene chloride
Sources & evidence
- ORD record
- ord-269ac4b146d64aeabcef2f6db67097bf
- Source dataset
- uspto-grants-2014_02
- Patent number
- US08658637B2
Reaction notes
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