反应详情

温度

23 °C

NBS (Aldrich; 1.201 g, 6.75 mmol) was added in one portion to a solution of methyl 1H-pyrrole-3-carboxylate (Aldrich; 0.844 g, 6.75 mmol) in THF (10 mL), and the resulting solution was stirred at 23° C. for 1.5 h. THF was removed in vacuo, and the residue was taken up in DCM (50 mL) and washed with 10:1 water/sat. aq. NaHCO3 (50 mL). The organic layer was separated, and the aq. layer was extracted with DCM (2×40 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated onto silica gel. Chromatographic purification (silica gel, 0-50% EtOAc/hexanes) furnished methyl 5-bromo-1H-pyrrole-3-carboxylate (924.2 mg, 4.53 mmol, 67% yield) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.41 (1H, br. s.), 7.36 (1H, dd, J=2.9, 1.8 Hz), 6.60 (1H, dd, J=2.5, 1.8 Hz), 3.81 (3H, s). m/z (ESI, +ve) 203.9/205.9 (M+H)+.

1. customTHF was removed in vacuo
2. washwashed with 10:1 water/
3. customThe organic layer was separated
4. extractionthe aq. layer was extracted with DCM (2×40 mL)
5. dry with materialThe combined organic extracts were dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated onto silica gel
8. customChromatographic purification (silica gel, 0-50% EtOAc/hexanes)