Hydrazine hydrate (1:1) → 6-fluoro-1H-indazol-3-amine

HRID 1875889Notes

Reaction equation

HRID 1875889 reaction equation
F[C:2]1[CH:9]=[C:8]([F:10])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5].O.[NH2:12][NH2:13]>>[F:10][C:8]1[CH:9]=[C:2]2[C:3]([C:4]([NH2:5])=[N:12][NH:13]2)=[CH:6][CH:7]=1

Participants

3

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 775452,4-Difluorobenzonitrile

Product 1

HCID 219392676-fluoro-1H-indazol-3-amineYield 38%

Procedure

To 2,4-difluorobenzonitrile (1.21 g, 8.70 mmol) was added hydrazine monohydrate (8.46 mL, 174 mmol). The mixture was heated to reflux for 5 hours and then poured onto ice. The solution was extracted with ethyl acetate, dried with magnesium sulfate, filtered and concentrated. The residue was purified by column chromatography (25-100% ethyl acetate/hexane) to afford 6-fluoro-1H-indazol-3-amine (0.5 g, 3.3 mmol, 38% yield) as light yellow powder. 1H NMR (500 MHz, DMSO-D6) δ ppm 11.42 (s, 1H), 7.70 (dd, J=8.55, 5.49 Hz, 1H), 6.97 (dd, J=10.07, 1.83 Hz, 1H), 6.72-6.79 (m, 1H), 5.40 (s, 2H). MS (LC/MS) R.T.=0.61; [M+H]+=152.11.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 5 hours
  3. additionpoured onto ice
  4. extractionThe solution was extracted with ethyl acetate
  5. dry with materialdried with magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by column chromatography (25-100% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-378b72669b3e41d98cea9ca465345eb1
Source dataset
uspto-grants-2012_11
Patent number
US08309577B2

Reaction notes

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