Dimethylformamide → Ethyl 3-(benzyloxy)-1-methyl-1H-pyrazole-4-carboxylate

HRID 1295219Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1295219
[OH:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][N:4]([CH3:12])[N:3]=1.[CH2:13](Br)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C(=O)([O-])[O-].[K+].[K+].CN(C)C=O>O>[CH2:13]([O:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][N:4]([CH3:12])[N:3]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Komponenten

6

Edukt 4

HCID 6228DimethylformamideHCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 178469818HCID 178469818, Verbindung

Produkt 1

HCID 22175079Ethyl 3-(benzyloxy)-1-methyl-1H-pyrazole-4-carboxylateAusbeute 82 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Reaktionsbedingungen

Temperatur
50 °C

Versuchsvorschrift

A mixture of ethyl 3-hydroxy-1-methyl-1H-pyrazole-4-carboxylate (25.50 g), benzyl bromide (17.8 ml), potassium carbonate (31.10 g) and N,N-dimethylformamide (250 ml) was stirred overnight at 50° C. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was dilute hydrochloric acid, washed with saturated brine, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography, and ethyl 3-benzyloxy-1-methyl-1H-pyrazole-4-carboxylate (31.90 g, yield 82%) was obtained as a colorless crystal from a fraction eluted with ethyl acetate-hexane (1:1, volume ratio) and recrystallized from ethyl acetate-hexane. melting point: 66–67° C.

Aufarbeitung

  1. extractionthe mixture was extracted with ethyl acetate
  2. washwashed with saturated brine
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated

Quellen und Nachweise

ORD-Eintrag
ord-11786f95964a45ac9eeff59b3e79fee2
Quelldatensatz
uspto-grants-2007_07
Patentnummer
US07241785B2

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