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. 1M 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