反应详情

A mixture of 3-oxo-butyric acid ethyl ester (7 mL, 53.7 mmol), aniline (5 g, 53.7 mmol), acetic acid (0.060 mL) and 4 Å molecular sieves (5 g) in EtOH (20 mL) was refluxed for 5 h. After cooling to r.t., the mixture was filtered. EtOAc was added to rinse the solids, and the filtrate was concentrated to give a reddish oil, which was purified by silica gel chromatography (0-10% EtOAc/hexanes) to give 7 g of the title compound as a pale yellow oil. 1H NMR (CDCl3, 200 MHz): δ=10.38 (br s, 1H), 7.00-7.40 (m, 5H), 4.69 (s, 1H), 4.15 (q, 2H, J=7.0 Hz), 2.00 (s, 3H), 1.29 (t, 3H, J=7.0 Hz).

1. temperaturewas refluxed for 5 h
2. filtrationthe mixture was filtered
3. additionEtOAc was added
4. washto rinse the solids
5. concentrationthe filtrate was concentrated
6. customto give a reddish oil, which
7. customwas purified by silica gel chromatography (0-10% EtOAc/hexanes)