Methyl iodide → 5-Bromo-1-methyl-1H-indazole

HRID 241083

Reaction equation

HRID 241083 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][N:6]=[CH:5]2.[C:11](=O)([O-])[O-].[Cs+].[Cs+].IC>CN(C)C=O>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([CH3:11])[N:6]=[CH:5]2

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 7619295-bromo-1H-indazole

Product 1

HCID 225587255-Bromo-1-methyl-1H-indazoleYield 70%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A suspension of 5-bromo-1H-indazole (200 mg, 1.02 mmol), cesium carbonate (661 mg, 2.00 mmol), and iodomethane (156 mg, 1.10 mmol) in dimethylformamide (3 mL) was stirred at room temperature for 15 h. The mixture was partitioned between 5% lithium chloride and ethyl acetate, the aqueous layer was extracted with ethyl acetate (2×), the combined organic extracts were washed with 1 N sodium hydroxide, and brine, dried over anhydrous sodium sulfate, filtered and concentrated. Column chromatography on silica (hexanes/ethyl acetate 4:1) gave 5-bromo-1-methyl-1H-indazole (150 mg, 70% yield) as an orange solid. MS (EI) for C8H7BrN2: 212 (MH+).

Workup

  1. customThe mixture was partitioned between 5% lithium chloride and ethyl acetate
  2. extractionthe aqueous layer was extracted with ethyl acetate (2×)
  3. washthe combined organic extracts were washed with 1 N sodium hydroxide, and brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-16eb5aa2b9ae4a53ac49ff40dc23ac45
Source dataset
uspto-grants-2014_02
Patent number
US08648066B2

Linked notes

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