N-bromobutanimide → Methyl 5-bromo-1H-pyrrole-3-carboxylate

HRID 1056300Notes

Reaction equation

HRID 1056300 reaction equation
C1C(=O)N([Br:8])C(=O)C1.[NH:9]1[CH:13]=[CH:12][C:11]([C:14]([O:16][CH3:17])=[O:15])=[CH:10]1>C1COCC1>[Br:8][C:13]1[NH:9][CH:10]=[C:11]([C:14]([O:16][CH3:17])=[O:15])[CH:12]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 12361759methyl 1H-pyrrole-3-carboxylate

Product 1

HCID 23271158Methyl 5-bromo-1H-pyrrole-3-carboxylateYield 67.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
23 °C

Procedure

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)+.

Workup

  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)

Sources & evidence

ORD record
ord-7e3d1a7fdd664c2093193c74ff0a0b55
Source dataset
uspto-grants-2016_07
Patent number
US09394297B2

Reaction notes

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