反应详情

Ammonium acetate (185 mg, 2.4 mmol) was added to a solution of ethyl 2-(acetylamino)-3-oxobutanoate (90 mg, 0.48 mmol) in acetic acid (1.0 mL). The mixture was heated to reflux overnight. After cooling, the solvent was evaporated under reduced pressure and the residue was taken up in saturated sodium bicarbonate and extracted with EtOAc. The organic layer was dried over sodium sulfate, and concentrated. The residue was purified by column chromatography (0-4% 2M NH3 solution of MeOH in DCM) to give the title compound (54 mg, 67%) as a white solid. 1H NMR (400 MHz, CDCl3-d) δ ppm 4.30 (q, J=7.20 Hz, 2H) 2.44 (s, 3H) 2.38 (s, 3H) 1.34 (t, J=7.14 Hz, 3H). LCMS: m/z 169 (M+1).

1. temperatureThe mixture was heated
2. temperatureto reflux overnight
3. temperatureAfter cooling
4. customthe solvent was evaporated under reduced pressure
5. extractionextracted with EtOAc
6. dry with materialThe organic layer was dried over sodium sulfate
7. concentrationconcentrated
8. customThe residue was purified by column chromatography (0-4% 2M NH3 solution of MeOH in DCM)