Acetic Anhydride → ethyl 2-(5-acetamido-3-phenyl-1H-pyrazol-1-yl)acetate

HRID 1615727Notes

Reaction equation

HRID 1615727 reaction equation
[NH2:1][C:2]1[N:6]([CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])[N:5]=[C:4]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:3]=1.[C:19](OC(=O)C)(=[O:21])[CH3:20]>N1C=CC=CC=1>[C:19]([NH:1][C:2]1[N:6]([CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])[N:5]=[C:4]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:3]=1)(=[O:21])[CH3:20]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 820314ethyl 2-(5-amino-3-phenyl-1H-pyrazol-1-yl)acetate

Product 1

HCID 86717316ethyl 2-(5-acetamido-3-phenyl-1H-pyrazol-1-yl)acetateYield 45%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of ethyl 2-(5-amino-3-phenyl-pyrazol-1-yl)acetate (49 g, 0.17 mol) in pyridine (200 mL) was added acetic anhydride (17.4 g, 0.17 mol) dropwise at 0° C. under an atmosphere of nitrogen. The reaction mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated in vacuo. The residue was diluted with CH2Cl2 and water. The layers were separated and the organic layer was washed with water and brine, dried (MgSO4) and concentrated in vacuo. CH2Cl2 was added to the residue and the solid was collected by filtration, yielding the title compound as a solid (22 g). The mother liquors were concentrated in vacuo and washed with cold CH2Cl2 to yield a second batch of 15 g.

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. additionThe residue was diluted with CH2Cl2 and water
  3. customThe layers were separated
  4. washthe organic layer was washed with water and brine
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated in vacuo
  7. additionCH2Cl2 was added to the residue
  8. filtrationthe solid was collected by filtration

Sources & evidence

ORD record
ord-34952eff153f4ec59fc53a7d6ca767d7
Source dataset
uspto-grants-2014_07
Patent number
US08765762B2

Reaction notes

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