1H-Pyrazole,3-methyl-5-phenyl- → 4-bromo-3-methyl-5-phenyl-1H-pyrazole

HRID 1471907Notes

Reaction equation

HRID 1471907 reaction equation
[CH3:1][C:2]1[NH:6][N:5]=[C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[CH:3]=1.[Br:13]Br>ClCCl>[Br:13][C:3]1[C:4]([C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][CH:12]=2)=[N:5][NH:6][C:2]=1[CH3:1]

Participants

4

Reactant 2

HCID 187741H-Pyrazole,3-methyl-5-phenyl-HCID 24408Bromine

Product 1

HCID 7443354-bromo-3-methyl-5-phenyl-1H-pyrazoleYield 79.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 5-methyl-3-phenyl-1H-pyrazole (8.0 g, 50.6 mmol) in dichloromethane (150 mL) was added bromine (8.08 g, 50.6 mmol) dropwise at 0° C. The reaction was stirred at that temperature for 30 min and continued at room temperature for 2 h. After quenched with aqueous solution of Na2SO3 (10% wt aq., 10 mL), the organic solvent was removed and the aqueous mixture was extracted with EtOAc, washed with brine, dried over MgSO4, and concentrated. The residue was purified by silica gel column chromatography to give the title compound as yellow oil (9.5 g). LCMS m/z=236.9 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.26 (s, 3H), 7.30-7.57 (m, 5H), 13.12 (s, 1H).

Workup

  1. waitcontinued at room temperature for 2 h
  2. customAfter quenched with aqueous solution of Na2SO3 (10% wt aq., 10 mL)
  3. customthe organic solvent was removed
  4. extractionthe aqueous mixture was extracted with EtOAc
  5. washwashed with brine
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated
  8. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-d7619221c69e49929e55c006425bdbff
Source dataset
uspto-grants-2015_04
Patent number
US09012478B2

Reaction notes

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