Potassium Hydroxide → 4-(ethoxycarbonyl)-3,5-dimethyl-1H-pyrrole-2-carboxylic acid

HRID 638249Notes

Reaction equation

HRID 638249 reaction equation
[CH3:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[C:5]([CH3:12])[NH:4][C:3]=1[C:13]([O:15]CC)=[O:14].[OH-].[K+]>C(O)C.O>[CH3:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[C:5]([CH3:12])[NH:4][C:3]=1[C:13]([OH:15])=[O:14]

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 75526Diethyl 2,4-dimethylpyrrole-3,5-dicarboxylate

Product 1

HCID 2247094-(ethoxycarbonyl)-3,5-dimethyl-1H-pyrrole-2-carboxylic acidYield 90%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 962WaterSolvent

Procedure

To a solution of 23,9 g (0.1 mol) of diethyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate in 300 ml of hot ethanol was added a solution of 14 g (0.25 mol) of potassium hydroxide in 350 ml of water. The solution was boiled and the ethanol was allowed to evaporate. After 1.5 hours, the volume was reduced by 350 ml then cooled, filtered, and acidified with 2 N hydrochloric acid. A precipitate formed which was collected, washed with water, and dried to give 19 g of 3,5-dimethyl-4-ethoxycarbonyl-1H-pyrrolecarboxylic acid. This acid was disolved in quinoline, 5 g of powdered copper was added, and the mixture heated to 200° C. during which time carbon dioxide was released. The residue was distilled (0.1 mm/120°-140° C.) and the distillate recrystallized (ethyl ether/pentane) to give the title compound, m.p. 74°-76° C.

Workup

  1. customto evaporate
  2. temperaturethen cooled
  3. filtrationfiltered
  4. customA precipitate formed which
  5. customwas collected
  6. washwashed with water
  7. customdried

Sources & evidence

ORD record
ord-f35457a356e84ad6b464ec6a518c06e9
Source dataset
uspto-grants-1985_12
Patent number
US04560700

Reaction notes

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