反应详情

温度

-5 °C

To a solution of 5.68 g of BOC-Ala-OH, 10.12 g of H-Gly-OBzl.TosOH and 4.0 g of HOBT dissolved in 50 ml of THF, under cooling at -5° C., was added 5.5 ml of WSC, and the mixture was stirred at -5° C. for one hour and at room temperature overnight. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in ethyl acetate. The ethyl acetate layer was washed successively twice with 1N hydrochloric acid, twice with 5% aqueous sodium hydrogen carbonate and with water. After drying over anhydrous magnesium sulfate, the product was concentrated under reduced pressure. The residue was crystallized from n-hexane, then recrystallized twice from ethyl acetate-n-hexane to give 9.32 g (yield: 92.3%) of BOC-Ala-Gly-OBzl melting at 85°-87° C. Rf1 =0.54.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. dissolutionthe residue was dissolved in ethyl acetate
3. washThe ethyl acetate layer was washed successively twice with 1N hydrochloric acid, twice with 5% aqueous sodium hydrogen carbonate and with water
4. dry with materialAfter drying over anhydrous magnesium sulfate
5. concentrationthe product was concentrated under reduced pressure
6. customThe residue was crystallized from n-hexane
7. customrecrystallized twice from ethyl acetate-n-hexane