反应详情

A solution of methyl 3-oxo-2-(pivalamido)butanoate (0.22 g, 1.0 mmol) in phosphorus oxychloride (1.5 mL) was heated at 110° C. for 30 min. The reaction was cooled in an ice bath, and saturated aqueous NaHCO3 was slowly added until the mixture was basic. The reaction was extracted with CH2Cl2, and the extracts were washed with saturated aqueous NaHCO3 and water, dried over Na2SO4, and concentrated under vacuum. The residue was purified by silica gel chromatography (0%-40% EtOAc-hexanes) to obtain methyl 2-tert-butyl-5-methyloxazole-4-carboxylate (44 mg, 22% yield). 1H NMR (400 MHz, CDCl3) δ 3.90 (s, 3H, 2.60 (s, 3H), 1.39 (s, 9H) ppm. LC/MS: m/z 198.3 (M+H)+ at 2.83 min (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA)).

1. temperatureThe reaction was cooled in an ice bath
2. extractionThe reaction was extracted with CH2Cl2
3. washthe extracts were washed with saturated aqueous NaHCO3 and water
4. dry with materialdried over Na2SO4
5. concentrationconcentrated under vacuum
6. customThe residue was purified by silica gel chromatography (0%-40% EtOAc-hexanes)