Ammonia → Ethyl 2-methyl-3-pyrrolecarboxylate

HRID 1782215Notes

Reaction equation

HRID 1782215 reaction equation
C(O[CH:5]=[CH2:6])(=O)C.BrBr.O=[C:10]([CH3:17])[CH2:11][C:12]([O:14][CH2:15][CH3:16])=[O:13].[NH3:18]>O>[CH3:17][C:10]1[NH:18][CH:5]=[CH:6][C:11]=1[C:12]([O:14][CH2:15][CH3:16])=[O:13]

Participants

6

Reactant 4

HCID 222AmmoniaHCID 7904Vinyl AcetateHCID 8868Ethyl AcetoacetateHCID 24408Bromine

Product 1

HCID 136747Ethyl 2-methyl-3-pyrrolecarboxylateYield 35%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Vinyl acetate (13.4 g) was added dropwise over 2 hr to bromine (25 g) under ice-cooling with stirring. The reaction mixture was further stirred at the same temperature for 1 hr. Ethyl 3-oxobutanoate (18.5 g) was added, and 25% aqueous ammonia solution (44 mL) was added dropwise over 1 hr. The reaction mixture was further stirred at room temperature for 30 min, water was added and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→3:1) and recrystallized from hexane to give the title compound as a colorless solid (yield 7.56 g, 35%).

Workup

  1. temperaturecooling
  2. stirringThe reaction mixture was further stirred at the same temperature for 1 hr
  3. stirringThe reaction mixture was further stirred at room temperature for 30 min
  4. extractionthe mixture was extracted with ethyl acetate
  5. washThe extract was washed with saturated brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→3:1)
  9. customrecrystallized from hexane

Sources & evidence

ORD record
ord-8906695c0511400ab6aa653e9d58e236
Source dataset
uspto-grants-2009_03
Patent number
US07498337B2

Reaction notes

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