反应详情

Boc-Gly-Ala-OH was prepared by an N-hydroxysuccinimide coupling procedure. Boc-Gly-OSu (7.67 g, 28.2 mmol) was dissolved in 10 mL of dimethylsulfoxide and the resulting solution was added to a solution consisting of H-Ala-OH (3.76 g, 42.3 mmol) and triethylamine (5.89 mL, 42.3 mmol) in 20 mL of water. After stirring overnight, a precipitate was removed by filtration. The remaining solution was diluted with water and then acidified with hydrochloric acid. An aqueous phase separated from which product was extracted by addition of ethyl acetate. The ethyl acetate extract was washed with 0.2N hydrochloric acid and then saturated sodium chloride prepared in 0.2N hydrochloric acid. The washed ethyl acetate solution was then dried over sodium sulfate and filtered. Solvent was then evaporated, leaving a foamy product, which was crystallized from ethyl acetate:hexane to yield 2.88 g of Boc-Gly-Ala-OH (m.p. 128°-130°).

1. additionthe resulting solution was added to a solution
2. customa precipitate was removed by filtration
3. additionThe remaining solution was diluted with water
4. customAn aqueous phase separated from which product
5. extractionwas extracted by addition of ethyl acetate
6. extractionThe ethyl acetate extract
7. washwas washed with 0.2N hydrochloric acid
8. customsaturated sodium chloride prepared in 0.2N hydrochloric acid
9. dry with materialThe washed ethyl acetate solution was then dried over sodium sulfate
10. filtrationfiltered
11. customSolvent was then evaporated
12. customleaving a foamy product, which
13. customwas crystallized from ethyl acetate