Potassium Hydroxide → 2,4-Dimethyl-5-carboxy-1H-pyrrole-3-propanoic acid 5-ethyl ester

HRID 24330Notes

Reaction equation

[CH3:1][C:2]1[NH:3][C:4]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[C:5]([CH3:14])[C:6]=1[CH2:7][CH2:8][C:9]([O:11]CC)=[O:10].[OH-].[K+]>O.CO>[CH2:18]([O:17][C:15]([C:4]1[NH:3][C:2]([CH3:1])=[C:6]([CH2:7][CH2:8][C:9]([OH:11])=[O:10])[C:5]=1[CH3:14])=[O:16])[CH3:19]

Participants

Conditions

Temperature: 70 °C

Procedure

To a suspension of 10 g (38.9 mmol) ethyl 2,4-dimethyl-5-(ethoxycarbonyl)-3-pyrrolepropionate (commercially available) in a mixture of water (250 mL) and methanol (MeOH) (50 mL) was added 3.0 g of KOH in 50 mL of water. The mixture was stirred at 70° C. for 4 hr. The reaction mixture was cooled and the methanol was stripped from the mixture under vacuum. The remaining solution was filtered and the filtrate was then acidified with 6N hydrochloric acid to pH 3. The precipitate which formed was collected by filtration, washed with a 2:1 mixture of water and ethanol and dried under vacuum to give 7.5 g of 4-(2-carboxy-ethyl)-3,5-dimethyl-1H-pyrrole-2-carboxylic acid ethyl ester as a white solid.

Workup

temperatureThe reaction mixture was cooled
filtrationThe remaining solution was filtered
customThe precipitate which formed
filtrationwas collected by filtration
washwashed with a 2:1 mixture of water and ethanol
customdried under vacuum

Sources & evidence

ORD record: ord-b83993ba834544a5b266a7678a49131a
Source dataset: uspto-grants-2005_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06855730B2

Reaction notes

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