反应详情

To a solution of (i) (156 mg, 0.32 mmol) and acetic acid (37 μL, 0.64 mmol) in anhydrous 1,4-dioxane (15 mL) and water (20 mL) at 0° C. was added NBS (68 mg, 0.13 mmol) in a single portion. The reaction mixture was allowed to warm slowly to room temperature over 1 h 25 min whereupon aq. 1 M NaOH solution (3 mL) was added and the reaction followed LCMS analysis. After 30 min, the reaction mixture was diluted with water (10 mL), extracted with EtOAc (3×10 mL) and the combined organics then dried (MgSO4) and concentrated in vacuo to obtain (ii) (191 mg, >100%). The crude product was used without further purification in the next step. ESI-MS m/z calculated for [M+H]+ 503.2. found: 503.1.

1. additionwas added
2. extractionextracted with EtOAc (3×10 mL)
3. dry with materialthe combined organics then dried (MgSO4)
4. concentrationconcentrated in vacuo