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

Participants

Reaction Steps

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.

Provenance & Evidence