反应详情

To a suspension consisting of 2.3 g of H-Asp-OEt, 5.8 g of Boc-Thr(Bzl)-OSu in 20 ml of THF and 20 ml of DMF, was added 2 ml of triethylamine under an ice-cooling condition and the mixture was stirred for 1 hour so as to the pH of the reaction mixture was adjusting to about pH 7, and the reaction was continued for 36 hours. The reaction mixture was concentrated under reduced pressure and the residue thus obtained was acidified by adding 1N-hydrochloric acid, and 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, The ethyl acetate extract was concentrated under reduced pressure and the residue thus obtained was crystallized and recrystallized from diethyl ether-petroleum ether. 5.59 Grams (yield: 86.6%) of the above-mentioned objective product was obtained.

1. temperaturecooling condition
2. waitthe reaction was continued for 36 hours
3. concentrationThe reaction mixture was concentrated under reduced pressure
4. customthe residue thus obtained
5. extractionextracted 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. extractionThe ethyl acetate extract
9. concentrationwas concentrated under reduced pressure
10. customthe residue thus obtained
11. customwas crystallized
12. customrecrystallized from diethyl ether-petroleum ether