Potassium Hydroxide → 4,5,6,7-Tetrahydropyrazolo[1,5-a]pyridin-2-amine

HRID 1080413Notes

Reaction equation

HRID 1080413 reaction equation
[OH-].[K+].Cl.NO.CC1[N:8]([C:13]2[CH:21]=[C:16]3[CH2:17][CH2:18][CH2:19][CH2:20][N:15]3[N:14]=2)C(C)=CC=1>O.C(O)C>[NH2:8][C:13]1[CH:21]=[C:16]2[CH2:17][CH2:18][CH2:19][CH2:20][N:15]2[N:14]=1

Participants

6

Reactant 3

HCID 14797Potassium HydroxideHCID 443297Hydroxyamine hydrochlorideHCID 54312166HCID 54312166, compound

Product 1

HCID 543166624,5,6,7-Tetrahydropyrazolo[1,5-a]pyridin-2-amine

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 962WaterSolvent

Procedure

A solution of 8.19 g (146 mmol) potassium hydroxide in 122 ml water and 122 ml ethanol was added to 19.19 g (292 mmol) hydroxylamine hydrochloride in 200 ml ethanol. The mixture was stirred for 15 minutes, 12.5 g (58 mmol) 2-(2,5-dimethyl-1-pyrrolyl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine added and the mixture heated under reflux for 30 hours. After distilling the ethanol, the mixture was treated with ethyl acetate, solid material filtered off, the aqueous phase saturated with sodium chloride and extracted with ethyl acetate. The organic phase was washed with saturated aqueous sodium chloride, dried over sodium sulfate and concentrated. The crude product was purified by silica gel chromatography (ethyl acetate/methanol).

Workup

  1. temperaturethe mixture heated
  2. temperatureunder reflux for 30 hours
  3. distillationAfter distilling the ethanol
  4. additionthe mixture was treated with ethyl acetate, solid material
  5. filtrationfiltered off
  6. extractionthe aqueous phase saturated with sodium chloride and extracted with ethyl acetate
  7. washThe organic phase was washed with saturated aqueous sodium chloride
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated
  10. customThe crude product was purified by silica gel chromatography (ethyl acetate/methanol)

Sources & evidence

ORD record
ord-5769847db5e449ad8ee66668fe8d2930
Source dataset
uspto-grants-1996_12
Patent number
US05580986

Reaction notes

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