Hydrazine → 7-chloro-6-fluoro-1H-pyrazolo[4,3-b]pyridine

HRID 1522566Notes

Reaction equation

HRID 1522566 reaction equation
[Cl:1][C:2]1[C:7]([F:8])=[CH:6][N:5]=[C:4]([CH:9]=O)[C:3]=1F.[NH2:12][NH2:13]>CCCCO>[Cl:1][C:2]1[C:7]([F:8])=[CH:6][N:5]=[C:4]2[CH:9]=[N:12][NH:13][C:3]=12

Participants

4

Reactant 2

HCID 9321HydrazineHCID 848197844-Chloro-3,5-difluoropicolinaldehyde

Product 1

HCID 674705117-chloro-6-fluoro-1H-pyrazolo[4,3-b]pyridine

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent

Conditions

Temperature
110 °C

Procedure

To a solution of 4-chloro-3,5-difluoropicolinaldehyde (533 mg, 3.0 mmol) in n-BuOH (15 mL) was added hydrazine (0.113 mL, 3.60 mmol) and the reaction was heated at 110° C. for 22 hours. The reaction mixture was cooled, concentrated and the residue was dissolved in EtOAc (100 mL) and washed with saturated Na2CO3 solution, dried over Na2SO4, and evaporated to give a residue which was purified by silica gel column chromatography eluted with hexanes/EtOAc (0-100%) to give the title compound. MS [M+H] found 172.0.

Workup

  1. temperatureThe reaction mixture was cooled
  2. concentrationconcentrated
  3. dissolutionthe residue was dissolved in EtOAc (100 mL)
  4. washwashed with saturated Na2CO3 solution
  5. dry with materialdried over Na2SO4
  6. customevaporated
  7. customto give a residue which
  8. customwas purified by silica gel column chromatography
  9. washeluted with hexanes/EtOAc (0-100%)

Sources & evidence

ORD record
ord-3aead7e3af944aacb7c1b09d00ba84ca
Source dataset
uspto-grants-2015_07
Patent number
US09073918B2

Reaction notes

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