反应详情

温度

25 °C

A suspension of β-alanine ethyl ester hydrochloride salt (2.0 g, 13.0 mmol), 4-fluorobenzaldehyde (1.61 g, 13.0 mmol), sodium acetate (2.13 g, 26.0 mmol), and 4 Å molecular sieves (0.5 g/mmol) in methanol (50 mL) was treated with sodium cyanoborohydride (1.63 g, 26.0 mmol). The reaction was stirred at 25° C. for 4 h, diluted with a saturated aqueous sodium bicarbonate solution (150 mL), and extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated in vacuo. The crude oil was purified by flash column chromatography (ISCO RediSep column, 20 to 70% ethyl acetate in hexanes) to give 3-(4-fluoro-benzylamino)-propionic acid ethyl ester (2.08 g, 71%) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ: 1.26 (t, 3H, J=7.0 Hz), 2.52 (t, 2H, J=6.5 Hz), 2.88 (t, 2H, J=6.2 Hz), 3.76 (s, 2H), 4.14 (q, 2H, J=6.8 Hz), 6.96-7.01 (m, 2H), 7.26-7.28 (m, 2H). LC-MS (ESI) calculated for C12H11FNO2: 225.3, found 226.2 [M+H+].

1. extractionextracted with ethyl acetate (3×50 mL)
2. dry with materialThe combined organic layers were dried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customThe crude oil was purified by flash column chromatography (ISCO RediSep column, 20 to 70% ethyl acetate in hexanes)