Hydrazine → HCID 178437989, compound

HRID 1880376Notes

Reaction equation

HRID 1880376 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](F)=[C:6]([C:8](=O)[CH2:9][CH3:10])[CH:7]=1.[NH2:13][NH2:14]>>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[NH:14][N:13]=[C:8]2[CH2:9][CH3:10]

Participants

3

Reactant 2

HCID 9321HydrazineHCID 529838141-(5-Bromo-2-fluorophenyl)propan-1-one

Product 1

HCID 178437989HCID 178437989, compoundYield 40%

Conditions

Temperature
72.5 °C

Procedure

To 1-(5-bromo-2-fluorophenyl)propan-1-one (10 g, 43 mmol), anhydrous hydrazine (53 mL) was added and heated at reflux (70-75° C.) for 2 days. Excess hydrazine was distilled out under vacuum from the reaction mixture. To this was added xylene (60 mL) and the mixture heated to 145-150° C. for 3 days. Xylene was concentrated completely under vacuum to give a crude product, which was purified by column chromatography using 8% ethyl acetate/pet-ether as eluents to afford 5-bromo-3-ethyl-1H-indazole (4 g, 40%) as a solid. 1H NMR (CDCl3): δ 9.6-10.0 (br, 1H), 7.9 (s, 1H), 7.5 (d, 1H), 7.3 (d, 1H), 3.0 (q, 2H), 1.4 (t, 3H).

Workup

  1. temperatureheated
  2. distillationExcess hydrazine was distilled out under vacuum from the reaction mixture
  3. additionTo this was added xylene (60 mL)
  4. temperaturethe mixture heated to 145-150° C. for 3 days
  5. concentrationXylene was concentrated completely under vacuum
  6. customto give a crude product, which
  7. customwas purified by column chromatography

Sources & evidence

ORD record
ord-192d127c814b4945a66f6968a13ff888
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

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