Hydrochloric Acid → 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic Acid

HRID 349862Notes

Reaction equation

HRID 349862 reaction equation
C([O:3][C:4]([C:6]1[C:10]([CH3:11])=[C:9]([CH:12]=[O:13])[NH:8][C:7]=1[CH3:14])=[O:5])C.[OH-].[K+].Cl>CO.O>[CH:12]([C:9]1[NH:8][C:7]([CH3:14])=[C:6]([C:4]([OH:5])=[O:3])[C:10]=1[CH3:11])=[O:13]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 137485ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate

Product 1

HCID 110737925-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic AcidYield 95.7%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

5-Formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester (2 g, 10 mmol) was added to a solution of potassium hydroxide (3 g, 53 mmol) dissolved in methanol (3 mL) and water (10 mL). The mixture was refluxed for 3 hours, cooled to room temperature and acidified with 6 N hydrochloric acid to pH 3. The solid was collected by filtration, washed with water and dried in a vacuum oven overnight to give 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (1.6 g, 93%). 1H NMR (300 MHz, DMSO-d6) δ 12.09 (s, br, 2H, NH & COOH), 9.59 (s, 1H, CHO), 2.44 (s, 3H, CH3), 2.40 (s, 3H, CH3).

Workup

  1. temperatureThe mixture was refluxed for 3 hours
  2. filtrationThe solid was collected by filtration
  3. washwashed with water
  4. customdried in a vacuum oven overnight

Sources & evidence

ORD record
ord-8676fe0035b44176a2b69f494f41b4cf
Source dataset
uspto-grants-2007_02
Patent number
US07179910B2

Reaction notes

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