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

HRID 1653957Notes

Reaction equation

HRID 1653957 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

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

Workup

  1. temperatureheated for 30 hours
  2. temperatureunder reflux
  3. customAfter removal of the ethanol the mixture
  4. additionwas treated with ethyl acetate
  5. filtrationfiltered from solid material
  6. extractionthe aqueous phase saturated with sodium chloride and extracted with ethyl acetate
  7. washwith washed with saturated aqueous sodium chloride
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated
  10. customThe crude product was purified by silica gel column chromatography (ethyl acetate/methanol

Sources & evidence

ORD record
ord-c21eed0be6e84765b09010a83008ad78
Source dataset
uspto-grants-1995_04
Patent number
US05405829

Reaction notes

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