Trifluoroacetic anhydride → ethyl 2-[(E)-2-phenylethenyl]-1,3-oxazole-4-carboxylate

HRID 459449

Reaction equation

HRID 459449 reaction equation
C(=O)([O-])O.[Na+].Br[CH2:7][C:8](=O)[C:9]([O:11][CH2:12][CH3:13])=[O:10].[C:15]([NH2:25])(=[O:24])[CH:16]=[CH:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.FC(F)(F)C(OC(=O)C(F)(F)F)=O>O1CCCC1.C(OCC)(=O)C>[CH2:12]([O:11][C:9]([C:8]1[N:25]=[C:15](/[CH:16]=[CH:17]/[C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[O:24][CH:7]=1)=[O:10])[CH3:13]

Participants

7

Reactant 4

HCID 9845Trifluoroacetic anhydrideHCID 121352-Propenamide, 3-phenyl-HCID 66144Ethyl bromopyruvateHCID 516892Sodium Bicarbonate2×

Product 1

HCID 5708074ethyl 2-[(E)-2-phenylethenyl]-1,3-oxazole-4-carboxylate

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

Synthesis was conducted in accordance with the report (J. Org. Chem., 1996, Vol. 61, p. 6496) by Panek et al. Sodium hydrogencarbonate (22.8 g) and ethyl bromopyruvate (10.5 ml) were added to a solution of cinnamamide (10.0 g) in tetrahydrofuran (250 ml) at room temperature, and the mixture was heated under reflux for 48 hours. The reaction mixture was allowed to cool to room temperature, filtered through Celite and then concentrated under reduced pressure to obtain residue. Trifluoroacetic anhydride (30 ml) was added to a solution of this residue in tetrahydrofuran (30 ml) at 0° C., and the mixture was gradually warmed to room temperature. After the mixture was stirred for 63 hours, a saturated aqueous solution (500 ml) of sodium hydrogencarbonate and ethyl acetate (150 ml) were added to the reaction mixture, and an organic layer was separated. The water layer was extracted with ethyl acetate (150 ml). The organic layers were combined, washed with saturated saline (150 ml), dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (hexane:ethyl acetate=5:1→3:1) to obtain the title compound (10.9 g) as a colorless solid.

Workup

  1. customSynthesis
  2. temperaturethe mixture was heated
  3. temperatureunder reflux for 48 hours
  4. filtrationfiltered through Celite
  5. concentrationconcentrated under reduced pressure
  6. customto obtain residue
  7. temperaturethe mixture was gradually warmed to room temperature
  8. customan organic layer was separated
  9. extractionThe water layer was extracted with ethyl acetate (150 ml)
  10. washwashed with saturated saline (150 ml)
  11. dry with materialdried over anhydrous sodium sulfate
  12. concentrationconcentrated under reduced pressure
  13. customThe residue was purified by column chromatography on silica gel (hexane:ethyl acetate=5:1→3:1)

Sources & evidence

ORD record
ord-fc5c9af7705f487cbf9d9a1ec913ba62
Source dataset
uspto-grants-2007_03
Patent number
US07192968B2

Linked notes

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