Hydrazine, ethyl-, ethanedioate (1:1) → HCID 117992935, compound

HRID 922581Notes

Reaction equation

HRID 922581 reaction equation
[Br:1][C:2]1[CH:9]=[C:8]([F:10])[C:5]([CH:6]=O)=[C:4](F)[CH:3]=1.C(O)(=O)C(O)=O.[CH2:18]([NH:20][NH2:21])[CH3:19]>CN1C(=O)CCC1>[Br:1][C:2]1[CH:3]=[C:4]2[C:5]([CH:6]=[N:21][N:20]2[CH2:18][CH3:19])=[C:8]([F:10])[CH:9]=1

Participants

4

Reactant 2

HCID 96181Hydrazine, ethyl-, ethanedioate (1:1)HCID 27732904-Bromo-2,6-difluorobenzaldehyde

Product 1

HCID 117992935HCID 117992935, compoundYield 84%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent

Procedure

To a solution of 4-bromo-2,6-difluorobenzaldehyde (1000 mg, 4.5 mmol) in NMP (10 mL) was added ethyl hydrazine oxalate (747 mg, 5.0 mmol). The reaction mixture was stirred at r.t. for 72 h. The reaction mixture was heated under reflux for 15 h. After being cooled at r.t., the reaction mixture was partitioned between heptane and water. The aqueous layer was extracted with heptane. The combined organic extracts were washed with brine, dried over MgSO4, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (0-20% EtOAc in heptanes) to afford 6-bromo-1-ethyl-4-fluoro-1H-indazole as a light yellow oil (902 mg, 84%).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 15 h
  3. temperatureAfter being cooled at r.t.
  4. customthe reaction mixture was partitioned between heptane and water
  5. extractionThe aqueous layer was extracted with heptane
  6. washThe combined organic extracts were washed with brine
  7. dry with materialdried over MgSO4
  8. concentrationconcentrated under reduced pressure
  9. customThe crude product was purified by silica gel column chromatography (0-20% EtOAc in heptanes)

Sources & evidence

ORD record
ord-fea7e4d8a2e6486c904e5fa1d42dea6c
Source dataset
uspto-grants-2016_03
Patent number
US09278953B2

Reaction notes

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