Pyrazole → 1-(4-Nitrobenzyl)-1H-pyrazole

HRID 1508881Notes

Reaction equation

HRID 1508881 reaction equation
[N+:1]([C:4]1[CH:11]=[CH:10][C:7]([CH2:8]Br)=[CH:6][CH:5]=1)([O-:3])=[O:2].[NH:12]1[CH:16]=[CH:15][CH:14]=[N:13]1.C(=O)([O-])[O-].[K+].[K+]>C(#N)C.O>[N+:1]([C:4]1[CH:11]=[CH:10][C:7]([CH2:8][N:12]2[CH:16]=[CH:15][CH:14]=[N:13]2)=[CH:6][CH:5]=1)([O-:3])=[O:2]

Participants

6

Reactant 3

HCID 1048PyrazoleHCID 11430Potassium CarbonateHCID 660114-Nitrobenzyl bromide

Product 1

HCID 9736631-(4-Nitrobenzyl)-1H-pyrazoleYield 81%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Procedure

A mixture of 4-nitrobenzyl bromide (0.500 g, 2.31 mmol), 1H-pyrazole (0.362 g, 5.23 mmol), and potassium carbonate (0.704 g, 5.09 mmol) in acetonitrile (30 mL) was stirred at rt overnight. After this time, the mixture was diluted with water and extracted with ethyl acetate. The combined organic layer was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated. The residue was purified by column chromatography (silica, hexanes/ethyl acetate) to afford the title compound (0.380 g, 76%) as a white solid. MW=203.20. 1H NMR (CDCl3, 500 MHz) δ 8.21-8.19 (m, 1H), 8.19-8.16 (m, 1H), 7.61-7.57 (m, 1H), 7.48-7.44 (m, 1H), 7.32-7.28 (m, 2H), 6.35 (t, J=2.1 Hz, 1H), 5.44 (s, 2H); APCI MS m/z 204 [M+H]+.

Workup

  1. extractionextracted with ethyl acetate
  2. dry with materialThe combined organic layer was dried over anhydrous sodium sulfate
  3. filtrationfiltered
  4. concentrationthe filtrate was concentrated
  5. customThe residue was purified by column chromatography (silica, hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-4f3eb4d6f2754893a5fe6e8c1a885ee1
Source dataset
uspto-grants-2015_12
Patent number
US09221843B2

Reaction notes

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