Reaktion #86833

Reaktionsgleichung

Triethylamine

2-amino-1-phenylethanone hydrochloride

ethyl 2-chloro-2-oxoacetate

→

ethyl 5-phenyloxazole-2-carboxylate

Ausbeute 22.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe organic layer was washed successively with a saturated aqueous solution of sodium carbonate, and water
2. 2
   TrocknenThe organic layer was dried over magnesium sulfate
3. 3
   Einengenwas concentrated under reduced pressure
4. 4
   workup.DISSOLUTIONThe crude residue was dissolved in phosphorus (V) oxychloride (10 mL)
5. 5
   Temperaturthe solution was refluxed for 4 hours
6. 6
   TemperaturAfter cooling
7. 7
   Sonstigethe volatiles were removed under reduced pressure
8. 8
   workup.DISSOLUTIONthe residue was dissolved in dichloromethane
9. 9
   WaschenThe organic layer was then carefully washed with a saturated aqueous solution of sodium carbonate
10. 10
    Trocknendried over magnesium sulfate
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    SonstigeThe residue was purified by flash chromatography on silica gel (eluent 15 to 100% dichloromethane in heptane)

Vorschrift

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.

Quelle