Acetic Anhydride → 1-(2-Phenylpyrazolo[1,5-a]pyridin-3-yl)-1-ethanone

HRID 1534125Notes

Reaction equation

HRID 1534125 reaction equation
[C:1]1([C:7]2[CH:15]=[C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][N:9]3[N:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[C:16](OC(=O)C)(=[O:18])[CH3:17]>S(=O)(=O)(O)O.[OH-].[Na+]>[C:1]1([C:7]2[C:15]([C:16](=[O:18])[CH3:17])=[C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][N:9]3[N:8]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 156203422-Phenylpyrazolo[1,5-a]pyridine

Product 1

HCID 107049561-(2-Phenylpyrazolo[1,5-a]pyridin-3-yl)-1-ethanoneYield 47.7%

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 14798Sodium HydroxideSolvent

Procedure

2-Phenylpyrazolo[1,5-a]pyridine (2.00 g) was added to a stirred solution of acetic anhydride (4.20 g) and two drops of sulfuric acid at room temperature. After being stirred under reflux for 14 hours, the reaction mixture was poured onto 80 ml of 4N NaOH aqueous solution and extracted with chloroform (30 ml×2). The extracts were combined and washed with water (30 ml), saturated sodium chloride aqueous solution (30 ml), then dried over magnesium sulfate and evaporated in vacuo. The residual crystals were recrystallized from diisopropyl ether to give 2-phenyl-3-acetylpyrazolo[1,5-a]pyridine (1.16 g).

Workup

  1. temperatureunder reflux for 14 hours
  2. extractionextracted with chloroform (30 ml×2)
  3. washwashed with water (30 ml), saturated sodium chloride aqueous solution (30 ml)
  4. dry with materialdried over magnesium sulfate
  5. customevaporated in vacuo
  6. customThe residual crystals were recrystallized from diisopropyl ether

Sources & evidence

ORD record
ord-6b9a136eab444e618bd28fb8ef2570d0
Source dataset
uspto-grants-1992_02
Patent number
US05087629

Reaction notes

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