Acetic Anhydride → 1-[2-(Propan-2-yl)pyrazolo[1,5-a]pyridin-3-yl]ethan-1-one

HRID 839792Notes

Reaction equation

HRID 839792 reaction equation
[CH:1]([C:4]1[CH:12]=[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][N:6]2[N:5]=1)([CH3:3])[CH3:2].[C:13](OC(=O)C)(=[O:15])[CH3:14]>S(=O)(=O)(O)O.[OH-].[K+]>[C:13]([C:12]1[C:4]([CH:1]([CH3:3])[CH3:2])=[N:5][N:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=12)(=[O:15])[CH3:14]

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 113786582-Isopropylpyrazolo[1,5-a]pyridine

Product 1

HCID 159338551-[2-(Propan-2-yl)pyrazolo[1,5-a]pyridin-3-yl]ethan-1-oneYield 81.1%

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 14797Potassium HydroxideSolvent

Procedure

A mixture of 4.2g of 2-isopropylpyrazolo[1,5-a]-pyridine, 10.2g of acetic anhydride and 2-3 drops of concentrated sulfuric acid was refluxed for 7 hr. After cooling, the mixture was added to 200 ml of 4M potassium hydroxide solution and stirred for 1 hr. The solution was extracted with chloroform and the chloroform solution was dried over sodium sulfate. The dried chloroform solution was concentrated and the residue was columnchromatographed over alumina to isolate objective product. Recrystallization from n-hexane gave 4.3g of colorless needles, mp 74° C. Yield 67%.

Workup

  1. temperaturewas refluxed for 7 hr
  2. temperatureAfter cooling
  3. extractionThe solution was extracted with chloroform
  4. dry with materialthe chloroform solution was dried over sodium sulfate
  5. concentrationThe dried chloroform solution was concentrated
  6. customto isolate objective product
  7. customRecrystallization from n-hexane

Sources & evidence

ORD record
ord-7501d1dc34534a46a42280ac97b4d82c
Source dataset
uspto-grants-1978_06
Patent number
US04097483

Reaction notes

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