反应详情

Iron powder (0.44 g, 7.8 mmol) was added to a solution of methyl N-[(3-chloro-4′-nitrobiphenyl-4-yl)carbonyl]-L-valinate (0.30 g, 0.78 mmol) in ethanol (10 mL). Concentrated HCl (0.39 mL, 0.78 mmol) was added, and the mixture was heated at reflux for 3 h. Upon cooling to rt, the mixture was filtered through a pad of Celite®, and the filtrate was concentrated in vacuo. The material was purified by column chromatography (33% EtOAc in hexanes), yielding 0.25 g (89%) of the title compound. LC/MS m/z/z 361.2 (MH+), retention time 2.36 min. 1H NMR (400 MHz, CD2Cl2) δ 1.06 (dd, 6H), 2.32-2.39 (m, 1H), 3.80 (s, 3H), 4.71-4.78 (m, 1H), 6.82 (d, 3H), 7.40-7.74 (m, 5H).

1. temperaturethe mixture was heated
2. temperatureat reflux for 3 h
3. filtrationthe mixture was filtered through a pad of Celite®
4. concentrationthe filtrate was concentrated in vacuo
5. customThe material was purified by column chromatography (33% EtOAc in hexanes)