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

HRID 497933Notes

Reaction equation

HRID 497933 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 mixture was heated under reflux for 3.5 hours. After the mixture was allowed to cool to room temperature, the reaction solvent was evaporated under reduced pressure and water was added to the residue. After the solution was made basic by the addition of an aqueous sodium hydroxide solution, 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. Purification of the residue by silica gel column chromatography (ethyl acetate) gave the title compound (156.3 g, 90% yield).

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 3.5 hours
  3. customthe reaction solvent was evaporated under reduced pressure and water
  4. additionwas added to the residue
  5. additionAfter the solution was made basic by the addition of an aqueous sodium hydroxide solution, 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. customPurification of the residue by silica gel column chromatography (ethyl acetate)

Sources & evidence

ORD record
ord-608a2beee47140a2a93a373efc43f977
Source dataset
uspto-grants-2005_09
Patent number
US06949648B2

Reaction notes

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