反应详情

To a stirred solution of 23 (crude) (0.588 mmol) in CH2Cl2 (2.9 mL) at 0 degrees were added Boc-Ala-OSu (185 mg, 0.647 mmol) and triethylamine (0.18 mL, 1.3 mmol). The mixture was allowed to reach 21° C. slowly, stirring for 16 h at room temperature. The solvent was then evaporated. The mixture was quenched with a saturated ammonium chloride solution and extracted with ethyl acetate, washed with brine, dried (MgSO4) filtered and concentrated. The residue was purified by silica gel column chromatography with gradient of EtOAc (20-60%) in hexanes to afford 24 (140 mg, 49%) as a white solid. LRMS (ESI): calc. 484.1; found 507.2 (MNa)+.

1. customto reach 21° C.
2. customThe solvent was then evaporated
3. customThe mixture was quenched with a saturated ammonium chloride solution
4. extractionextracted with ethyl acetate
5. washwashed with brine
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by silica gel column chromatography with gradient of EtOAc (20-60%) in hexanes