Diethyl Oxalate → ethyl 1'H,2H-[3,3'-bipyrazole]-5-carboxylate

HRID 1409347Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1409347
[Na].[NH:2]1[C:6]([C:7](=O)[CH3:8])=[CH:5][CH:4]=[N:3]1.[C:10]([O:17][CH2:18][CH3:19])(=[O:16])[C:11](OCC)=O.Cl.[NH2:21][NH2:22].[OH-].[Na+]>O.C(O)C>[NH:21]1[C:11]([C:10]([O:17][CH2:18][CH3:19])=[O:16])=[CH:8][C:7]([C:6]2[NH:2][N:3]=[CH:4][CH:5]=2)=[N:22]1

Komponenten

8

Edukt 5

HCID 7268Diethyl OxalateHCID 14798Sodium HydroxideHCID 115031Hydrazinium chlorideHCID 3334711-(1H-pyrazol-3-yl)ethan-1-oneHCID 5360545Sodium2×

Produkt 1

HCID 70981238ethyl 1'H,2H-[3,3'-bipyrazole]-5-carboxylateAusbeute 22,8 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 702EthanolLösungsmittelHCID 962WaterLösungsmittel

Reaktionsbedingungen

Temperatur
75 °C

Versuchsvorschrift

Pieces of sodium (0.26 g) were slowly added to ethanol (12 ml) with stirring until all sodium had dissolved. 1-(1H-Pyrazol-5-yl)ethanone (8.61 mmol, 0.948 g) and diethyl oxalate (8.61 mmol, 1.258 g) was added. The mixture was heated to 75° C. for 3 h after which the stirring continued at RT overnight. Hydrazine hydrochloride (8.61 mmol, 0.590 g) dissolved in water (6 ml) was added. The resulting mixture was again heated to 75° C. for 3 h. The mixture was cooled to RT and neutralized by adding 2 M NaOH. The mixture was extracted twice with EtOAc and the combined organics were washed with water and brine. The organic phase was dried, filtered and evaporated. The crude product was purified by flash chromatography. 0.404 g of the title compound was obtained. 1H-NMR (400 MHz, MeOH-d4): δ 1.39 (t, 3H), 4.38 (q, 2H), 6.69 (d, 1H), 7.10 (bs, 1H), 7.70 (bs, 1H).

Aufarbeitung

  1. dissolutionhad dissolved
  2. additionwas added
  3. temperatureThe resulting mixture was again heated to 75° C. for 3 h
  4. temperatureThe mixture was cooled to RT
  5. extractionThe mixture was extracted twice with EtOAc
  6. washthe combined organics were washed with water and brine
  7. customThe organic phase was dried
  8. filtrationfiltered
  9. customevaporated
  10. customThe crude product was purified by flash chromatography

Quellen und Nachweise

ORD-Eintrag
ord-9bb17615e04145528bfd3b139301a72d
Quelldatensatz
uspto-grants-2014_12
Patentnummer
US08921378B2

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