Water → 1-benzyl-4-nitro-1H-indazole

HRID 79261

Reaktionsgleichung

Reaktionsgleichung von HRID 79261
[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[N:7][NH:8]2)([O-:3])=[O:2].C(=O)([O-])[O-].[K+].[K+].[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.O>CN(C=O)C>[CH2:19]([N:8]1[C:9]2[C:5](=[C:4]([N+:1]([O-:3])=[O:2])[CH:12]=[CH:11][CH:10]=2)[CH:6]=[N:7]1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Komponenten

6

Edukt 4

HCID 962WaterHCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 180574-Nitroindazole

Produkt 1

HCID 213272561-benzyl-4-nitro-1H-indazoleAusbeute 47 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6228DimethylformamideLösungsmittel

Versuchsvorschrift

To a solution of 4-nitro-1H-indazole (1.00 g; 6.13 mmol) in dry DMF (15 mL) under an atmosphere of dry nitrogen was added potassium carbonate (1.69 g; 12.3 mmol) and benzyl bromide (1.15 g; 6.74 mmol). The mixture was stirred at ambient temperature for 24 hours. Water (50 mL) was added and the mixture was extracted with ethyl acetate. The combined organic extracts were dried over sodium sulfate and filtered. The solvent was removed under reduced pressure to give a brown solid which was a mixture of two regioisomers. The desired isomer was separated by chromatography on silica (Biotage SNAP column, 100 g), eluting with hexane/ethyl acetate (20:1 to 10:1 to 5:1). The desired (N1) regioisomer was the first to elute. The fractions containing the desired product were evaporated under reduced pressure to give 1-benzyl-4-nitro-1H-indazole (730 mg) as a yellow solid.

Aufarbeitung

  1. extractionthe mixture was extracted with ethyl acetate
  2. dry with materialThe combined organic extracts were dried over sodium sulfate
  3. filtrationfiltered
  4. customThe solvent was removed under reduced pressure
  5. customto give a brown solid which
  6. additiona mixture of two regioisomers
  7. customThe desired isomer was separated by chromatography on silica (Biotage SNAP column, 100 g)
  8. washeluting with hexane/ethyl acetate (20:1 to 10:1 to 5:1)
  9. washto elute
  10. additionThe fractions containing the desired product
  11. customwere evaporated under reduced pressure

Quellen und Nachweise

ORD-Eintrag
ord-3fc1d941a04b47eca2f092e47ee991b7
Quelldatensatz
uspto-grants-2014_09
Patentnummer
US08841455B2

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