反应详情

A solution of -tyrosine t-butyl ester (Bachem, 20.0 g, 84.3 mmol) and FMOC-OSu (Bachem, 24.68 g, 71.2 mmol) was dissolved in 400 mL of dioxane and 400 mL of water. The pH of the resulting solution was adjusted to pH=9 and the solution stirred overnight at room temperature. The reaction mixture was concentrated to ½ volume and treated with concentrated HCl until the pH=5. The resulting solution was extracted with ethyl acetate (5×150 mL), the combined organic extracts were dried with MgSO4 and concentrated. The residue was crystallized from hot heptane/EtOAc. The solid that formed was collected by filtration and air dried to give the title compound (28.5 g, 87%) as a white solid.

1. concentrationThe reaction mixture was concentrated
2. additiontreated with concentrated HCl until the pH=5
3. extractionThe resulting solution was extracted with ethyl acetate (5×150 mL)
4. dry with materialthe combined organic extracts were dried with MgSO4
5. concentrationconcentrated
6. customThe residue was crystallized from hot heptane/EtOAc
7. customThe solid that formed
8. filtrationwas collected by filtration and air
9. customdried