Acetic Anhydride → 2-(4-Fluorophenyl)-3-acetylpyrazolo[1,5-a]pyridine

HRID 1374715Notes

Reaction equation

HRID 1374715 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:16]=[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][N:10]3[N:9]=2)=[CH:4][CH:3]=1.[OH-].[Na+].[C:19](OC(=O)C)(=[O:21])[CH3:20]>OS(O)(=O)=O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[C:16]([C:19](=[O:21])[CH3:20])=[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][N:10]3[N:9]=2)=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 14798Sodium HydroxideHCID 221748462-(4-Fluorophenyl)pyrazolo[1,5-a]pyridine

Product 1

HCID 179624172-(4-Fluorophenyl)-3-acetylpyrazolo[1,5-a]pyridine

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidCatalyst

Procedure

A mixture of 2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine (2.00 g, 9.42 mmol) in acetic anhydride (20 mL) and conc. H2SO4 (2 drops) was stirred and heated at reflux for 30 min. The mixture was cooled to room temperature, poured into ice water (300 mL), and basified (pH=10) using 1N NaOH(aq). The resulting orange precipitate was collected by filtration, washed with water, air-dried, then dried under high-vacuum to afford the title compound as an orange solid, 2.60 g (quant.). 1H NMR (CDCl3) δ 8.56 (d, 1H, J=6.9 Hz), 8.45 (d, 1H, J=9.3 Hz), 7.62 (m, 2H), 7.54 (m, 1H), 7.24 (m, 2H), 7.08 (m, 1H), 2.20 (s, 3H): MS (+ve ion electrospray) 255 (100), (MH+).

Workup

  1. temperatureheated
  2. temperatureat reflux for 30 min
  3. filtrationThe resulting orange precipitate was collected by filtration
  4. washwashed with water
  5. customair-dried
  6. customdried under high-vacuum

Sources & evidence

ORD record
ord-8bd8430f6b8246349e9740132fce31e3
Source dataset
uspto-grants-2007_01
Patent number
US07166597B2

Reaction notes

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