Nitrogen → (E)-ethyl 2-(1-phenylprop-1-en-2-yl)oxazole-4-carboxylate

HRID 1044760Notes

Reaction equation

HRID 1044760 reaction equation
N#N.[CH3:3]/[C:4](=[CH:8]\[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)/[C:5]([NH2:7])=[O:6].C([O-])(O)=O.[Na+].[CH2:20]([O:22][C:23](=[O:28])[C:24](=O)[CH2:25]Br)[CH3:21].FC(F)(F)C(OC(=O)C(F)(F)F)=O.C([O-])([O-])=O.[Na+].[Na+]>C1COCC1>[CH2:20]([O:22][C:23]([C:24]1[N:7]=[C:5](/[C:4](/[CH3:3])=[CH:8]/[C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[O:6][CH:25]=1)=[O:28])[CH3:21]

Participants

8

Reactant 6

HCID 947NitrogenHCID 9845Trifluoroacetic anhydrideHCID 10340Sodium CarbonateHCID 66144Ethyl bromopyruvate2×HCID 516892Sodium BicarbonateHCID 6243942(E)-2-methyl-3-phenylacrylamide

Product 1

HCID 66819964(E)-ethyl 2-(1-phenylprop-1-en-2-yl)oxazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a suspension of (E)-2-methyl-3-phenylacrylamide (29.4 g, 0.18 mol) and NaHCO3 (68.7 g, 0.82 mol) in THF (500 mL) was treated with 3-bromo-2-oxo-propionic acid ethyl ester (35.6 mL, 0.24 mol) and the reaction mixture was heated at reflux for 20 h. 3-Bromo-2-oxo-propionic acid ethyl ester (10.0 mL, 0.68 mol) was added again and the reaction mixture was stirred at reflux for 10 h. The reaction mixture was then filtered over celite and the solvents were evaporated under reduced pressure. The residue was dissolved in THF (500 mL) and treated at 0° C., dropwise, with trifluoroacetic anhydride (78.0 mL, 0.55 mol). The reaction mixture was then stirred at rt overnight. Sat. aq. Na2CO3 was added and the mixture was extracted with EA (4×), dried over MgSO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (0:1->1:9 EA-Hept) gave the title compound as a brown oil. TLC:rf (1:9 EA-Hept)=0.13. LC-MS-conditions 01: tR=1.02 min; [M+H]+=257.97.

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureat reflux for 20 h
  3. temperatureat reflux for 10 h
  4. filtrationThe reaction mixture was then filtered over celite
  5. customthe solvents were evaporated under reduced pressure
  6. dissolutionThe residue was dissolved in THF (500 mL)
  7. additiontreated at 0° C.
  8. stirringThe reaction mixture was then stirred at rt overnight
  9. extractionthe mixture was extracted with EA (4×)
  10. dry with materialdried over MgSO4
  11. filtrationfiltered
  12. customthe solvent was removed under reduced pressure
  13. customPurification of the residue by FC (0:1->1:9 EA-Hept)

Sources & evidence

ORD record
ord-3f9fd82c86ce476caeb17f3a750ab697
Source dataset
uspto-grants-2013_10
Patent number
US08563714B2

Reaction notes

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