Ethylene Glycol → 2,4-Dimethyl-3-carboxy-ethylpyrrole

HRID 2357710

Reaktionsgleichung

Reaktionsgleichung von HRID 2357710
C(OC([C:6]1[NH:7][C:8]([CH3:18])=[C:9]([CH2:12][CH2:13][C:14]([O:16]C)=[O:15])[C:10]=1[CH3:11])=O)C.[OH-:19].[K+].Cl.[CH2:22]([OH:25])[CH2:23]O>O>[CH3:18][C:8]1[NH:7][CH:6]=[C:10]([CH3:11])[C:9]=1[CH2:12][CH2:13][C:14]([OH:16])=[O:15].[CH3:13][CH2:12][CH2:9][C:8]1[NH:7][CH:6]=[C:10]([CH3:11])[C:23]=1[C:22]([OH:25])=[O:19]

Komponenten

7

Edukt 4

HCID 174Ethylene GlycolHCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 291754Ethyl 4-(3-methoxy-3-oxopropyl)-3,5-dimethyl-1H-pyrrole-2-carboxylate

Produkt 2

HCID 15125193-(2,4-dimethyl-1H-pyrrol-3-yl)propanoic AcidHCID 684626212,4-Dimethyl-3-carboxy-ethylpyrroleAusbeute 72 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel2×

Reaktionsbedingungen

Temperatur
190 °C

Versuchsvorschrift

2-(2-thienyl)pyrrole was prepared according to Kruse C. G. et al, Heterocycles 26 (1985) 3141 and formylated yielding 2-formyl-5-(2-thienyl)pyrrole according to Bullock E. et al. J. Chem. Soc. (1963) 2326 2,4-dimethyl-3-carboxyethylpyrrole was prepared as follows: 2-ethoxycarbonyl-3,5-dimethyl-4-methoxycarbonylethylpyrrole (1.5 g, 5.9 mmol) and potassium hydroxide (6.6 g) were dissolved in ethyleneglycol (50 ml). The reaction mixture was refluxed (190° C.) for 3 h under nitrogen atmosphere. Water (10 ml) was added and the mixture was refluxed for an additional 2 h. The cooled reaction mixture was diluted with water (200 ml), acidified with concentrated hydrochloric acid and extracted with diethylether. The organic extracts were pooled, dried with sodium sulphate and evaporated to dryness. The product was purified with column chromatography using silica as a stationary phase and dichloromethane:methanol (10:1, v:v) as an eluent. Fractions containing the product were pooled and evaporated to dryness yielding 720 mg (72%) of 2,4-dimethyl-3-carboxy-ethylpyrrole.

Aufarbeitung

  1. temperaturethe mixture was refluxed for an additional 2 h
  2. customThe cooled reaction mixture
  3. extractionextracted with diethylether
  4. dry with materialdried with sodium sulphate
  5. customevaporated to dryness
  6. customThe product was purified with column chromatography
  7. additionFractions containing the product
  8. customevaporated to dryness

Quellen und Nachweise

ORD-Eintrag
ord-34083cf7e4394fb3aaf8f264914e5418
Quelldatensatz
uspto-grants-2010_07
Patentnummer
US07763439B2

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