反应详情

温度

0 °C

Boc-Gly-OH (4.4 g, 0.025 mol.) and Nleu-OEt (3.2 g, 0.02 mol.) were dissolved in 100 ml DMF and the solution was chilled to 0° C. on a water-ice bath. BOP (11 g, 0.025 mol.) was added to the solution. Triethylamine was used to adjust the pH of the solution to about 9. The solution was stirred overnight. The DMF was removed under reduced pressure and the resulting mixture was poured into 300 ml ethyl acetate. The ethyl acetate solution was washed by H2O, saturated NaHCO3, brine, saturated NaHSO4 and brine again. The organic layer was dried by Na2SO4 and the ethyl acetate was removed under reduced pressure to get the crude product. Column chromatography (elution solvents: E/H, 2:1) was carried out to obtain the pure product (5.9 g, 94%). TLC Rf=0.52 (developing solvents: E/H, 2:1). 1H-NMR (360 MHz, DMSO-d6) δ6.74 (m, Gly-NH), 6.68 (m, Gly-NH), 4.18 (s, Nleu-α), 4.12 (q, ethyl ester-CH2), 4.04 (q, ethyl ester-CH2), 3.94 (s, Nleu-α), 3.79 (d, Gly-α), 3.65 (d, Gly-α), 3.07 (m, Nleu-β), 1.79 (m, 1H, Nleu-γ), 1.34 (s, 9H, Boc-CH3), 1.16 (m, ethyl ester-CH3), 0.87 (d, Nleu-δ), 0.78 (d, Nleu-δ).

1. customThe DMF was removed under reduced pressure
2. additionthe resulting mixture was poured into 300 ml ethyl acetate
3. washThe ethyl acetate solution was washed by H2O, saturated NaHCO3, brine, saturated NaHSO4 and brine again
4. dry with materialThe organic layer was dried by Na2SO4
5. customthe ethyl acetate was removed under reduced pressure
6. customto get the crude product
7. washColumn chromatography (elution solvents: E/H, 2:1)