反应详情

To a 100-mL round-bottomed flask was added benzyl(2-methyl-4-oxobutan-2-yl)carbamate (1.04 g, 4.42 mmol) and bis(2-methoxyethyl)amine (0.776 mL, 5.30 mmol, Sigma-Aldrich) in 1,2-dichloroethane (20 mL) followed by AcOH (0.3 mL). The mixture was stirred at RT for 10 min, then sodium triacetoxyborohydride (1.124 g, 5.30 mmol, Sigma-Aldrich) was added portion wise. The reaction was stirred at RT for 1 h. Sat. NaHCO3 (20 mL) was added slowly and the mixture was extracted with EtOAc (40 mL×3). The combined organic layers were dried (MgSO4), filtered and concentrated in vacuo. The residue was purified with silica gel chromatography (eluted with 10-90% EtOAc in Hex) to give benzyl(4-(bis(2-methoxyethyl)amino)-2-methylbutan-2-yl)carbamate (1.03 g, 2.92 mmol, 66% yield) as a colorless oil. MS (ESI, pos. ion) m/z: 353.1 (M+1); 1H NMR (400 MHz, CDCl3) δ ppm 7.27-7.40 (5H, m), 6.94 (1H, br. s.), 5.05 (2H, s), 3.45 (4H, t, J=5.8 Hz), 3.26 (6H, s), 2.64-2.73 (6H, m), 1.62 (2H, t, J=6.4 Hz), 1.36 (6H, s).

1. stirringThe reaction was stirred at RT for 1 h
2. extractionthe mixture was extracted with EtOAc (40 mL×3)
3. dry with materialThe combined organic layers were dried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified with silica gel chromatography (eluted with 10-90% EtOAc in Hex)