Potassium Hydroxide → 3-Acetyl-4,5-dimethyl-1H-pyrrole-2-carboxylic acid

HRID 2361572Notes

Reaction equation

HRID 2361572 reaction equation
C([O:3][C:4]([C:6]1[NH:7][C:8]([CH3:15])=[C:9]([CH3:14])[C:10]=1[C:11](=[O:13])[CH3:12])=[O:5])C.[OH-].[K+]>C(O)C>[C:11]([C:10]1[C:9]([CH3:14])=[C:8]([CH3:15])[NH:7][C:6]=1[C:4]([OH:5])=[O:3])(=[O:13])[CH3:12]

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 12288399Ethyl 3-acetyl-4,5-dimethyl-1H-pyrrole-2-carboxylate

Product 1

HCID 5906793-Acetyl-4,5-dimethyl-1H-pyrrole-2-carboxylic acidYield 81.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of pyrrole ester 4b (8.2 g, 0.0392 mol), in ethanol and 100 mL of 10% potassium hydroxide were refluxed for 1 hour. The mixture was cooled and concentrated in vacuo to an oil. Water was added to the oil, the mixture acidified with dilute HCl and extracted with ether. The organic phase was dried with anh. sodium sulfate and concentrated in vacuo to a solid residue. The compound was recrystallized in 80 mL of ethanol to give 5.8 g of pure 3-acetyl-4,5-dimethyl-2-pyrrole carboxylic acid 5b as a solid. 1H NMR (DMSO-d6) δ 2.5 (s, 3H), 2.2 (s, 3H), 2.0 (s, 3H) ppm.

Workup

  1. temperatureThe mixture was cooled
  2. concentrationconcentrated in vacuo to an oil
  3. additionWater was added to the oil
  4. extractionextracted with ether
  5. dry with materialThe organic phase was dried with anh. sodium sulfate
  6. concentrationconcentrated in vacuo to a solid residue
  7. customThe compound was recrystallized in 80 mL of ethanol

Sources & evidence

ORD record
ord-0fdd9ceb7c47472e9ac19a6d93179a45
Source dataset
uspto-grants-2014_04
Patent number
US08691758B2

Reaction notes

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