反应详情

To a mixture of DL-alanine ethyl ester hydrochloride (913 mg, 5.9 mmol) in DCE (15 mL) was added TEA (1.2 mL, 8.8 mmol) followed by benzaldehyde (0.538 mL), 5.3 mmol) and Na(OAc)3BH (2.0 g, 9.4 mmol). The mixture was stirred at room temperature overnight and then quenched with saturated aqueous NaHCO3 solution. The layers were separated and the aqueous layer extracted with DCM. The combined organic layers were dried over Na2SO4, filtered and concentrated in vacuo. Chromatography on SiO2 eluting EtOAc/Hex afforded the desired compound as a colorless liquid (798 mg, 73%). MS (ESI) mass calcd. C12H17NO2, 207.1. m/z found 208.2 [M+H]+. 1H NMR (500 MHz, CDCl3): 7.39-7.23 (m, 5H), 4.23-4.16 (m, 2H), 3.83-3.65 (m, 2H), 3.37 (q, J=7.0 Hz, 1H), 1.34-1.27 (m, 6H).

1. customquenched with saturated aqueous NaHCO3 solution
2. customThe layers were separated
3. extractionthe aqueous layer extracted with DCM
4. dry with materialThe combined organic layers were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. washChromatography on SiO2 eluting EtOAc/Hex