反应详情

To a solution of 4-tert-butoxycarbonylamino-2-(3,4-dichlorophenyl)-butyric acid methyl ester (12.3 g, 34 mmol) in THF (80 mL)/water (20 mL) was added lithium hydroxide (1.63 g, 68 mmol) at 0° C. The reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was concentrated and the residue diluted with water. After extraction with EtOAc, the aqueous phase was acidified to pH 5 by the addition of 2M aqueous hydrochloric acid solution. The aqueous phase was extracted with EtOAc and the extracts dried over magnesium sulfate. Concentration gave the title compound as a pale brown foam (11.54 g, 98%); 1H NMR (400 MHz, DMSO) δ 1.35 (9H, s), 1.74–1.81 (1H, m), 2.03–2.10 (1H, m), 2.81 (2H, m), 3.61 (1H, t), 6.86 (1H, m), 7.28 (1H, dd), 7.54 (1H, dd), 7.59 (1H, d), 12.60 (1H, brs); MS (ES−) m/e=346.

1. concentrationThe reaction mixture was concentrated
2. additionthe residue diluted with water
3. extractionAfter extraction with EtOAc
4. additionthe aqueous phase was acidified to pH 5 by the addition of 2M aqueous hydrochloric acid solution
5. extractionThe aqueous phase was extracted with EtOAc
6. dry with materialthe extracts dried over magnesium sulfate
7. concentrationConcentration