Benzyl Bromide → 2-Benzyl-2,4,5,6-tetrahydro-cyclopentapyrazole-3-carboxylic acid amide

HRID 475501Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 475501
[NH:1]1[C:5]2[CH2:6][CH2:7][CH2:8][C:4]=2[C:3]([C:9]([NH2:11])=[O:10])=[N:2]1.C([O-])([O-])=O.[K+].[K+].[CH2:18](Br)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>CN(C=O)C.CCOC(C)=O>[CH2:18]([N:2]1[C:3]([C:9]([NH2:11])=[O:10])=[C:4]2[CH2:8][CH2:7][CH2:6][C:5]2=[N:1]1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Komponenten

6

Edukt 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 451212581H,4H,5H,6H-cyclopenta[c]pyrazole-3-carboxamide

Produkt 1

HCID 587136472-Benzyl-2,4,5,6-tetrahydro-cyclopentapyrazole-3-carboxylic acid amideAusbeute 18,1 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6228DimethylformamideLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Versuchsvorschrift

To a stirring solution of 1,4,5,6-tetrahydro-cyclopentapyrazole-3-carboxylic acid amide (2.57 g, 17.0 mmol) in DMF (34 mL) at 25° C. was added K2CO3 (5.87 g, 42.5 mmol) followed by benzyl bromide (4.36 g g, 25.5 mmol). The reaction was stirred at ambient temperature for 16 h at which time the mixture was diluted with EtOAc (75 mL) and filtered. The filtrate was washed with H2O (100 mL) and the aqueous phase was back-extracted with EtOAc (75 mL) and CH2Cl2 (75 mL). The combined organic extracts were dried over MgSO4, filtered, and concentrated in vacuo. Purification by silica gel chromatography (50% EtOAc in hexanes gradient to 95% EtOAc in hexanes) gave 2-benzyl-2,4,5,6-tetrahydro-cyclopentapyrazole-3-carboxylic acid amide (739 mg, 3.07 mmol, 18% yield) isolated as a white solid followed by 1-benzyl-1,4,5,6-tetrahydro-cyclopentapyrazole-3-carboxylic acid amide (3.24 g, 13.4 mmol, 79% yield) isolated as a white solid.

Aufarbeitung

  1. filtrationfiltered
  2. washThe filtrate was washed with H2O (100 mL)
  3. extractionthe aqueous phase was back-extracted with EtOAc (75 mL) and CH2Cl2 (75 mL)
  4. dry with materialThe combined organic extracts were dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customPurification by silica gel chromatography (50% EtOAc in hexanes gradient to 95% EtOAc in hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-614abc68c85742719d31fd47f54b3dc9
Quelldatensatz
uspto-grants-2014_01
Patentnummer
US08637555B2

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