N-bromobutanimide → Methyl 2-(4-fluorophenyl)oxazole-4-carboxylate

HRID 875030Notes

Reaction equation

HRID 875030 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[O:9][CH2:10][CH:11]([C:13]([O:15][CH3:16])=[O:14])[N:12]=2)=[CH:4][CH:3]=1.BrN1C(=O)CCC1=O>C1C=CC=CC=1.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[O:9][CH:10]=[C:11]([C:13]([O:15][CH3:16])=[O:14])[N:12]=2)=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 22184737Methyl 2-(4-fluorophenyl)-4,5-dihydrooxazole-4-carboxylate

Product 1

HCID 53377469Methyl 2-(4-fluorophenyl)oxazole-4-carboxylateYield 67.3%

Reagents, catalysts & solvents 2

HCID 7187Benzoyl PeroxideCatalystHCID 241BenzeneSolvent

Procedure

Benzoyl peroxide (0.49 g, 2.0 mmol) was added to a solution of methyl 2-(4-fluorophenyl)-4,5-dihydrooxazole-4-carboxylate (9.0 g, 40.3 mmol) in dry benzene (180 mL) and the mixture was refluxed for 15 min. N-bromosuccinimide (8.6 g, 48.3 mmol) was then added and the reaction mixture was refluxed for 2 h. The reaction mixture was quenched with ice-cold water and the crude product was extracted with EtOAc. The combined extracts were washed with 10% aqueous NaHCO3 solution, H2O and brine, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica 60-120 mesh, eluant 10-15% EtOAc in petroleum ether) to get methyl 2-(4-fluorophenyl)oxazole-4-carboxylate (6 g, 67%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 8.29 (s, 1H), 8.14-8.10 (m, 2H), 7.19-7.15 (t, J=8.5 Hz, 2H), 3.96 (s, 3H). MS (ESI) m/z: Calculated for C11H8FNO3: 221.05. found: 221.8 (M+H)+

Workup

  1. temperaturethe mixture was refluxed for 15 min
  2. temperaturethe reaction mixture was refluxed for 2 h
  3. customThe reaction mixture was quenched with ice-cold water
  4. extractionthe crude product was extracted with EtOAc
  5. washThe combined extracts were washed with 10% aqueous NaHCO3 solution, H2O and brine
  6. dry with materialdried over anhydrous Na2SO4
  7. concentrationconcentrated under reduced pressure
  8. customThe crude product was purified by column chromatography (silica 60-120 mesh, eluant 10-15% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-78a1aa36f1384256a163ef5f39314d7b
Source dataset
uspto-grants-2015_03
Patent number
US08981084B2

Reaction notes

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