Methyl acetoacetate → Methyl 5-methyl-3-phenyl-1,2-oxazole-4-carboxylate

Beteiligte Stoffe

Reaktionsschritte

An ethanol solution of freshly prepared benzoyl chloride oxime (14.0 g, 90 mmol) (100 mL) was added dropwise, at 5° C. to methyl acetoacetate (11.18 g, 96 mmol) and triethyl amine (13 mL, 103 mmol) in ethanol (50 ml). After stirring for 12 hr at ambient temperature, the solution was diluted with CH2Cl2, washed with 1N HCl. saturated NaHCO3, brine, dried over MgSO4 and evaporated to give amber oil. Flash chromatography (silica) with 10% ethyl acetate in hexanes afforded the title compound (7.56 g, 39% yield) as a white solid: MS m/z MH+218 (100); 1H NMR (CDCl3) δ 2.78 (s, 3H), 3.81 (s, 3H), 7.45-7.55 (m, 3H), 7.65-7.69 (m, 2H).

Herkunft & Nachweise