Triethylamine → Ethyl 5-phenyl-1,3-oxazole-2-carboxylate

HRID 1918542Notes

Reaction equation

HRID 1918542 reaction equation
C(N(CC)CC)C.Cl.[NH2:9][CH2:10][C:11]([C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:12].Cl[C:20](=O)[C:21]([O:23][CH2:24][CH3:25])=[O:22]>ClCCl>[C:13]1([C:11]2[O:12][C:20]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[N:9][CH:10]=2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 20884Ethoxalyl chlorideHCID 2723597Ethanone, 2-amino-1-phenyl-, hydrochloride (1:1)

Product 1

HCID 13388477Ethyl 5-phenyl-1,3-oxazole-2-carboxylateYield 22%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Triethylamine (1.08 mL; 7.69 mmol) was added to a mixture of 2-amino-1-phenylethanone hydrochloride (0.550 g; 3.08 mmol) and ethyl 2-chloro-2-oxoacetate (0.369 mL; 3.23 mmol) in dichloromethane (10 mL) at 0° C. The reaction mixture was then stirred at room temperature for 22 hand diluted with dichloromethane (40 mL). The organic layer was washed successively with a saturated aqueous solution of sodium carbonate, and water. The organic layer was dried over magnesium sulfate and was concentrated under reduced pressure. The crude residue was dissolved in phosphorus (V) oxychloride (10 ml) and the solution was refluxed for 4 hours. After cooling, the volatiles were removed under reduced pressure and the residue was dissolved in dichloromethane. The organic layer was then carefully washed with a saturated aqueous solution of sodium carbonate, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (eluent 15 to 100% dichloromethane in heptane) to afford 0.146 g (22% overall yield) of ethyl 5-phenyloxazole-2-carboxylate as a solid.

Workup

  1. washThe organic layer was washed successively with a saturated aqueous solution of sodium carbonate, and water
  2. dry with materialThe organic layer was dried over magnesium sulfate
  3. concentrationwas concentrated under reduced pressure
  4. dissolutionThe crude residue was dissolved in phosphorus (V) oxychloride (10 ml)
  5. temperaturethe solution was refluxed for 4 hours
  6. temperatureAfter cooling
  7. customthe volatiles were removed under reduced pressure
  8. dissolutionthe residue was dissolved in dichloromethane
  9. washThe organic layer was then carefully washed with a saturated aqueous solution of sodium carbonate
  10. dry with materialdried over magnesium sulfate
  11. concentrationconcentrated under reduced pressure
  12. customThe residue was purified by flash chromatography on silica gel (eluent 15 to 100% dichloromethane in heptane)

Sources & evidence

ORD record
ord-20f766472f114884a6551e277d2ca50a
Source dataset
uspto-grants-2013_12
Patent number
US08618138B2

Reaction notes

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