Ammonia → Ethyl 2-methyl-3-pyrrolecarboxylate

HRID 2090614Notes

Reaction equation

HRID 2090614 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 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. additionwas added
  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-a69e41c3588844ea8a47ee3e4292fe20
Source dataset
uspto-grants-2013_05
Patent number
US08436187B2

Reaction notes

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