Ethyl Acetate → 3-Amino-5-bromo-1H-indazole

HRID 490104Notes

Reaction equation

HRID 490104 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](F)=[C:6]([CH:9]=1)[C:7]#[N:8].[NH2:11][NH2:12].C(OCC)(=O)C>C(O)C>[NH2:8][C:7]1[C:6]2[C:5](=[CH:4][CH:3]=[C:2]([Br:1])[CH:9]=2)[NH:12][N:11]=1

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 9321HydrazineHCID 27249005-Bromo-2-fluorobenzonitrile

Product 1

HCID 8179103-Amino-5-bromo-1H-indazoleYield 96.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
140 °C

Procedure

To a solution of 5-bromo-2-fluorobenzonitrile (0.40 g, 2.0 mmol.) in ethanol (3 mL) was added hydrazine (0.64 g, 20 mmol.). The reaction mixture was heated in a microwave reactor at 140° C. for 20 minutes. Ethyl acetate (100 mL) was added. The organic layer was washed with water and brine. The organic layer was dried over sodium sulfate. The organic solvent was evaporated under reduced pressure to yield 3-amino-5-bromoindazole 165 (0.41 g, 1.93 mmol.). The crude product was used in the next step without further purification.

Workup

  1. washThe organic layer was washed with water and brine
  2. dry with materialThe organic layer was dried over sodium sulfate
  3. customThe organic solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-c3a1255627004dadba6c59dd093873cb
Source dataset
uspto-grants-2009_05
Patent number
US07528132B2

Reaction notes

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