反应详情

To a suspension consisting of 2.3 g of H-Asp-OEt, 5.8 g of Boc-Thr(Bzl)-OSu, 20 ml of THF and 20 ml of DMF was added 2 ml of triethylamine under ice-cooling condition, and the mixture was stirred for 1 hour, then the pH of the reaction mixture was controlling to about pH 7, and the reaction was continued for 36 hours at room temperature. The reaction mixture was concentrated under reduced pressure, and the thus obtained residue was acidified by adding 1N-hydrochloric acid, then was extracted with ethyl acetate (80 ml×3 times). The organic layer was washed with water, then with a saturated sodium chloride aqueous solution, and dried over anhydrous magnesium sulfate, then concentrated under reduced pressure. Crystallized and recrystallized from diethyl ether-petroleum ether to obtain 5.59 g (yield: 86.6%) of the above-mentioned objective product.

1. temperaturecooling condition
2. waitthe reaction was continued for 36 hours at room temperature
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. additionby adding 1N-hydrochloric acid
5. extractionwas extracted with ethyl acetate (80 ml×3 times)
6. washThe organic layer was washed with water
7. dry with materialwith a saturated sodium chloride aqueous solution, and dried over anhydrous magnesium sulfate
8. concentrationconcentrated under reduced pressure
9. customCrystallized
10. customrecrystallized from diethyl ether-petroleum ether