Iodoethane → 2-Ethylindazole

HRID 278261Notes

Reaction equation

HRID 278261 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[N:2]1.[H-].[Na+].[CH2:12](I)[CH3:13]>CN(C=O)C>[CH2:12]([N:2]1[CH:3]=[C:4]2[C:9]([CH:8]=[CH:7][CH:6]=[CH:5]2)=[N:1]1)[CH3:13]

Participants

5

Reactant 3

HCID 6340IodoethaneHCID 92211H-IndazoleHCID 24758Sodium hydride

Product 1

HCID 122955192-EthylindazoleYield 30.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of indazole (6.2 g, 52.5 mmol) in DMF (30 mL) was added sodium hydride (60% dispersion in mineral oil, 3.0 g, 75.0 mmol) at 0° C. After stirring at 0° C. for 20 min., ethyl iodide (5 mL, 62.5 mmol) was added dropwise at 0° C. The mixture was stirred at rt for 1 h, and then partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate (3×). The combined organic phases were washed with brine, and dried over anhydrous magnesium sulfate. TLC indicated that a 2:1 mixture of two isomers was formed. The mixture was purified by flash chromatography (hexanes:ethyl acetate=4:1, then 1:1) to give 2.34 g of the title compound as a viscous oil (slow moving isomer).

Workup

  1. stirringThe mixture was stirred at rt for 1 h
  2. custompartitioned between ethyl acetate and water
  3. extractionThe aqueous layer was extracted with ethyl acetate (3×)
  4. washThe combined organic phases were washed with brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. additionTLC indicated that a 2:1 mixture of two isomers
  7. customwas formed
  8. customThe mixture was purified by flash chromatography (hexanes

Sources & evidence

ORD record
ord-a377e46b5bb940168d2edcedbe3dea05
Source dataset
uspto-grants-2002_03
Patent number
US06358979B1

Reaction notes

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