反应详情

12.5 g. (0.05 M) of Z-Pro-OH is converted to active ester as in Example 3 (a) and, with the addition of 5.7 ml. (0.06 M) of n-butylamine, it is stirred for 12 hours. The dioxane is distilled off under reduced pressure and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 5% NaHCO3 and 1N-HCl, followed by drying. The ethyl acetate is distilled off under reduced pressure and, following the addition of petroleum benzin, the residue is filtered. The crude product is recrystallized from ethyl acetate. Yield 14.0 g. (92.7%); melting point: 94.0°-95.0° C, optical rotation [α]D21 -39.6° (c=0.54, in N,N-dimethylformamide)

1. distillationThe dioxane is distilled off under reduced pressure
2. dissolutionthe residue is dissolved in ethyl acetate
3. washThe ethyl acetate layer is washed with 5% NaHCO3 and 1N-HCl
4. customby drying
5. distillationThe ethyl acetate is distilled off under reduced pressure
6. additionthe addition of petroleum benzin
7. filtrationthe residue is filtered
8. customThe crude product is recrystallized from ethyl acetate