Trifluoroacetic acid → 4-Allyl-2-(4-methoxy-phenyl)-5-methyl-oxazole

HRID 479142Notes

Reaction equation

HRID 479142 reaction equation
[C:1]([CH:4]([NH:8][C:9](=[O:18])[C:10]1[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][CH:11]=1)[CH2:5][CH:6]=[CH2:7])(=O)[CH3:2].FC(F)(F)C(O)=O.FC(F)(F)C(OC(=O)C(F)(F)F)=O>>[CH2:5]([C:4]1[N:8]=[C:9]([C:10]2[CH:11]=[CH:12][C:13]([O:16][CH3:17])=[CH:14][CH:15]=2)[O:18][C:1]=1[CH3:2])[CH:6]=[CH2:7]

Participants

4

Reactant 3

HCID 6422Trifluoroacetic acidHCID 9845Trifluoroacetic anhydrideHCID 18003598N-(1-Acetyl-but-3-enyl)-4-methoxy-benzamide

Product 1

HCID 180034954-Allyl-2-(4-methoxy-phenyl)-5-methyl-oxazoleYield 75.4%

Procedure

The above prepared N-(1-acetyl-but-3-enyl)-4-methoxy-benzamide (6.45 g, 26.1 mmol) was stirred in a mixture of 43.9 ml of trifluoro-acetic acid (22 eq.) and 21.75 ml of trifluoro-acetic anhydride (6 eq.) for 7 h at 40° and for 16 h at ambient temperature. Pouring onto crashed ice, twofold extraction with EtOEt, three times washing with Na2CO3-solution, drying over natrium sulfate and evaporation of the solvents, followed by flash chromatography (SiO2, hexane/AcOEt=9/1) produced finally 4.51 g of the title compound as colorless oil.

Workup

  1. additionPouring
  2. extractionice, twofold extraction with EtOEt, three times
  3. washwashing with Na2CO3-solution
  4. dry with materialdrying over natrium sulfate and evaporation of the solvents

Sources & evidence

ORD record
ord-2f4d3fe62f6f46bda5cd9b2561bfde75
Source dataset
uspto-grants-2003_11
Patent number
US06642389B2

Reaction notes

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