Potassium Hydroxide → 5-Formyl-4-methyl-1H-pyrrole-3-carboxylic acid

HRID 1839644Notes

Reaction equation

HRID 1839644 reaction equation
[OH-].[K+].C([O:5][C:6]([C:8]1[C:12]([CH3:13])=[C:11]([CH:14]=[O:15])[NH:10][CH:9]=1)=[O:7])C>O.CCO>[CH:14]([C:11]1[NH:10][CH:9]=[C:8]([C:6]([OH:7])=[O:5])[C:12]=1[CH3:13])=[O:15]

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 236067Ethyl 5-formyl-4-methyl-1h-pyrrole-3-carboxylate

Product 1

HCID 221354535-Formyl-4-methyl-1H-pyrrole-3-carboxylic acidYield 87.5%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

KOH (5 g, 2 eq) was added to a suspension of 5-formyl-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester (8.13 g, 44.8 mmol) in water (100 mL) and EtOH (50 mL) with stirring. The mixture was heated to reflux for 2.5 hr, cooled to rt, concentrated to about 2/3 volume, diluted with water (300 mL) and acidified to pH=3 using 1N HCl. The white solid was collected by filtration and dried to afford 6 g (87%) of 5-formyl-4-methyl-1H-pyrrole-3-carboxylic acid as a tan solid.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2.5 hr
  3. concentrationconcentrated to about 2/3 volume
  4. additiondiluted with water (300 mL)
  5. filtrationThe white solid was collected by filtration
  6. customdried

Sources & evidence

ORD record
ord-6bad67f71b204520b33da28850a96b2f
Source dataset
uspto-grants-2004_01
Patent number
US06677368B2

Reaction notes

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