Acetamide → Ethyl 2-methyl-1,3-oxazole-4-carboxylate

Temperature

85 °C

To a solution of acetamide (4.0 g) in tetrahydrofuran (300 ml) was added sodium hydrogen carbonate (28.4 g), followed by addition of 80% ethyl bromopyruvate (21.5 g) at 0° C. The mixture was heated at 85° C. overnight, the temperature was returned to room temperature, the insolubles were filtered using Celite and the solvent was evaporated under reduced pressure. The resulting residue was dissolved in tetrahydrofuran (150 ml), and to the solution was added dropwise trifluoroacetic anhydride at 0° C. After concentrated under reduced pressure, to the mixture was added ethyl acetate, and the mixture was washed with saturated sodium hydrogen carbonate solution twice and further with saturated brine and dried with magnesium sulfate. The solvent was evaporated under reduced pressure, followed by distillation under reduced pressure to give ethyl 2-methyloxazole-4-carboxylate (4.67 g).

1. customwas returned to room temperature
2. filtrationthe insolubles were filtered
3. customthe solvent was evaporated under reduced pressure
4. dissolutionThe resulting residue was dissolved in tetrahydrofuran (150 ml)
5. additionto the solution was added dropwise trifluoroacetic anhydride at 0° C
6. concentrationAfter concentrated under reduced pressure, to the mixture
7. additionwas added ethyl acetate
8. washthe mixture was washed with saturated sodium hydrogen carbonate solution twice
9. dry with materialfurther with saturated brine and dried with magnesium sulfate
10. customThe solvent was evaporated under reduced pressure
11. distillationfollowed by distillation under reduced pressure

ORD record

ord-f8e8d4547c5f47b6aea7580157f9f12a

Source dataset

uspto-grants-2005_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06936602B1