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

HRID 1359677Notes

Reaction equation

HRID 1359677 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 ⅔ 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 ⅔ volume
  4. additiondiluted with water (300 mL)
  5. filtrationThe white solid was collected by filtration
  6. customdried

Sources & evidence

ORD record
ord-fcb9a0ab90a14f548bd6870af6e8386d
Source dataset
uspto-grants-2003_07
Patent number
US06599902B2

Reaction notes

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