Acetic Anhydride → Methyl 5-methyl-1,3-oxazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of methyl isocyanoacetate (7.0 g, 70 mmol, 1 eq) and DBU (10.06 g, 70 mmol, 1 eq) in THF was cooled to 0° C., and a solution of acetic anhydride (7.14 g, 70 mmol, 1 eq) in THF was added dropwise over 15 min. The reaction mixture was stirred for 12 h at room temperature. The solvent was removed by Rota-vapor and water was added. The mixture was extracted with EtOAc. The crude product was purified by silica gel (230-400) column chromatography using 30% EtOAc/hexane. Yield: 6.8 g (98%). 1H NMR (400 MHz, CDCl3): δ 2.54 (s, 3H), 3.80 (s, 3H), 7.69 (s, 1H).

Provenance & Evidence