Acetic Acid → 3-Methyl-1-(pyridin-2-yl)-1H-pyrazol-5-amine

HRID 497977Notes

Reaction equation

HRID 497977 reaction equation
N/[C:2](=[CH:5]\[CH3:6])/[C:3]#[N:4].[NH:7]([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][N:10]=1)[NH2:8].C(O)(=O)C>C(O)C>[CH3:6][C:5]1[CH:2]=[C:3]([NH2:4])[N:7]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][N:10]=2)[N:8]=1

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 786452-HydrazinopyridineHCID 86589747Aminocrotononitrile

Product 1

HCID 7351323-Methyl-1-(pyridin-2-yl)-1H-pyrazol-5-amineYield 90%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To an ice-cold solution of aminocrotononitrile (82 g, 1.0 mol) and 2-hydrazinopyridine (120 g, 1.1 mol) in ethanol (300 mL) was added acetic acid (132 g, 2.2 mol), and the solution was heated under reflux for 3.5 hours. The solution was cooled to room temperature, and the solution was concentrated under reduced pressure, and water was added to the residue. The solution was made basic by the addition of an aqueous sodium hydroxide solution, and organic matter was extracted with ethyl acetate. The extract was washed with saturated brine and water, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate) to give the title compound (156.3 g, 90% yield).

Workup

  1. temperaturethe solution was heated
  2. temperatureunder reflux for 3.5 hours
  3. concentrationthe solution was concentrated under reduced pressure, and water
  4. additionwas added to the residue
  5. additionThe solution was made basic by the addition of an aqueous sodium hydroxide solution, and organic matter
  6. extractionwas extracted with ethyl acetate
  7. washThe extract was washed with saturated brine and water
  8. dry with materialdried over anhydrous magnesium sulfate
  9. customthe solvent was evaporated under reduced pressure
  10. customThe residue was purified by silica gel column chromatography (ethyl acetate)

Sources & evidence

ORD record
ord-11a61191044d4726b27d7684b8576fea
Source dataset
uspto-grants-2005_09
Patent number
US06949648B2

Reaction notes

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