Methylhydrazine → 1,5-Dimethyl-3-ethoxycarbonylpyrazole

HRID 1721825

Reaktionsgleichung

Reaktionsgleichung von HRID 1721825
[CH3:1][NH:2][NH2:3].O=[C:5]([CH2:11][C:12](=O)[CH3:13])[C:6]([O:8][CH2:9][CH3:10])=[O:7]>C(O)C>[CH3:1][N:2]1[C:12]([CH3:13])=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[N:3]1

Komponenten

4

Edukt 2

HCID 6061MethylhydrazineHCID 69208Ethyl 2,4-dioxovalerate

Produkt 1

HCID 1385771,5-Dimethyl-3-ethoxycarbonylpyrazole

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 702EthanolLösungsmittel

Versuchsvorschrift

9.2 ml of methylhydrazine was added dropwise over 30 minutes to a solution of 25 g of ethyl 2,4-dioxovalerate in 36 ml of ethanol, the temperature of the mixture being kept below 40° C. by cooling in an ice bath. The resulting solution was heated at reflux for 23 hours, poured into 300 ml of ice water and the resulting mixture was extracted with ether. The extract was dried (MgSO4), filtered and stripped of solvent. The residue was chromatographed on silica gel, with a 1:1 v:v mixture of ethyl acetate and hexane as eluent. The middle fractions gave ethyl 1,5-dimethylpyrazole-3-carboxylate (39A), as a yellow oil.

Aufarbeitung

  1. custombeing kept below 40° C.
  2. temperatureby cooling in an ice bath
  3. temperatureThe resulting solution was heated
  4. temperatureat reflux for 23 hours
  5. extractionthe resulting mixture was extracted with ether
  6. dry with materialThe extract was dried (MgSO4)
  7. filtrationfiltered
  8. customThe residue was chromatographed on silica gel, with a 1:1 v
  9. additionv mixture of ethyl acetate and hexane as eluent

Quellen und Nachweise

ORD-Eintrag
ord-ce029a6a88c749e598bcbe45ea6576fe
Quelldatensatz
uspto-grants-1989_08
Patentnummer
US04853027

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