反应详情

温度

10 °C

Crude 3-[4-(5-isoxazolyl)-phenyl]-alanine ethyl ester (660 mg) is dissolved in chloroform (6.6 ml), stirred vigorously with 2N aqueous sodium carbonate (1,4 ml), and after cooling to 10° C., 3,5-dimethylbenzoylchloride (0.7 ml) is added. Stirring is continued for 1 hour at 10° C. and for 2 hours at ambient temperature. Then extraction with dichloromethane/water, washing with 10% aqueous citric acid, and with brine, followed by evaporation gives the crude product. Flash chromatography on silica gel, hexane/ethyl acetate (4:1), gives pure N-(3,5-dimethylbenzoyl)-3-[4-(5-isoxazolyl)-phenyl]-alanine ethyl ester. NMR (CDCl3, 400 MHz) δ [ppm] 8.28 (d, 1.8 Hz, 1H), 7.72 (d, 8.2 Hz, 2H), 7.33 (s, 2H), 7.26 (d, 8.2 Hz, 2H), 7.15 (s, 1H), 6.65 (d, 7.3 Hz, 1H), 6.50 (d, 1.8 Hz, 1H), 5.09 (m, 1H), 4.24 (q, 7.1 Hz, 2H), 3.32 (m, 2H), 2.34 (s, 6H), 1.29 (t, 7.1 Hz, 3H).

1. extractionThen extraction with dichloromethane/water
2. washwashing with 10% aqueous citric acid
3. customwith brine, followed by evaporation
4. customgives the crude product