Hydrazine hydrate (1:1) → tert-Butyl 4-bromo-1H-indazole-5-carboxylate

HRID 79010Notes

Reaction equation

HRID 79010 reaction equation
[C:1]([O:5][C:6](=[O:17])[C:7]1[CH:12]=[CH:11][C:10](F)=[C:9]([CH:14]=O)[C:8]=1[Br:16])([CH3:4])([CH3:3])[CH3:2].O.[NH2:19][NH2:20]>COCCOC>[C:1]([O:5][C:6]([C:7]1[C:8]([Br:16])=[C:9]2[C:10](=[CH:11][CH:12]=1)[NH:20][N:19]=[CH:14]2)=[O:17])([CH3:4])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 575229892-Bromo-4-fluoro-3-formylbenzoic acid tert-butyl ester

Product 1

HCID 58374314tert-Butyl 4-bromo-1H-indazole-5-carboxylateYield 100%

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Procedure

A bi-phasic solution of 2-bromo-4-fluoro-3-formyl-benzoic acid tert-butyl ester (4.25 g, 14 mmol), DME (25 mL) and hydrazine hydrate (15 mL) was heated at 90° C. for 1 hour. After cooling, the products were partitioned between ethyl acetate and water, the aqueous layer extracted with ethyl acetate and the combined organic extracts dried (Na2SO4), filtered and concentrated in vacuo to give the title compound as a tan solid (4.1 g, 100%). LCMS (method B) RT=3.63 min, [M+CH3CN+H]+=338/340, [M−H]−=295/297.

Workup

  1. temperatureAfter cooling
  2. customthe products were partitioned between ethyl acetate and water
  3. extractionthe aqueous layer extracted with ethyl acetate
  4. dry with materialthe combined organic extracts dried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-5825fe85de04493493d5ff73180246e2
Source dataset
uspto-grants-2014_09
Patent number
US08841462B2

Reaction notes

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