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

HRID 983045

Reaction equation

HRID 983045 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-1ad93bea9e8d48e8afd14a00e43dc147
Source dataset
uspto-grants-2005_03
Patent number
US06861418B2

Linked notes

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