Toluene → 4-M-Bromophenyl-1-methylimidazole

HRID 653623Notes

Reaction equation

HRID 653623 reaction equation
COS(OC)(=O)=O.[Br:8][C:9]1[CH:10]=[C:11]([C:15]2[N:16]=[CH:17][NH:18][CH:19]=2)[CH:12]=[CH:13][CH:14]=1.[C:20]1(C)C=CC=CC=1.[OH-].[Na+]>O>[Br:8][C:9]1[CH:10]=[C:11]([C:15]2[N:16]=[CH:17][N:18]([CH3:20])[CH:19]=2)[CH:12]=[CH:13][CH:14]=1

Participants

6

Reactant 4

HCID 1140TolueneHCID 6497Dimethyl SulfateHCID 14798Sodium HydroxideHCID 178419377HCID 178419377, compound

Product 1

HCID 540817484-M-Bromophenyl-1-methylimidazoleYield 33%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

Using the method of Hazeldine et al., J. Chem. Soc., 125, 1431-41 (1924) a mixture of dimethylsulphate (145 μl, 1.53 mmol) and 4-m-bromophenyl imidazole (341 mg; 1.54 mmol) was stirred under N2 until the reaction mixture became extremely viscous. Toluene (150 μl) was added, and the mixture was heated at 100° C. for 1 hour. After cooling to ambient temperature, H2O (5 ml) was added, and the reaction mixture was brought to pH 9 with NaOH solution. It was then extracted with CH2Cl2 (2×10 ml). The organic layers were washed with brine, dried (MgSO4), and concentrated in vacuo to give 262 mg crude product mixed with starting material. Purification using preparative TLC on 2-1000μ Si Gel GF plates (eluting with 5% MeOH in CH2Cl2 and extracting with 10% MeOH in CH2Cl2) provided the product, 4-m-bromophenyl-1-methylimidazole (121 mg, 33% yield) as the least polar band.

Workup

  1. temperatureAfter cooling to ambient temperature
  2. extractionIt was then extracted with CH2Cl2 (2×10 ml)
  3. washThe organic layers were washed with brine
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated in vacuo
  6. customto give 262 mg crude product
  7. additionmixed with starting material
  8. customPurification
  9. washon 2-1000μ Si Gel GF plates (eluting with 5% MeOH in CH2Cl2 and extracting with 10% MeOH in CH2Cl2)

Sources & evidence

ORD record
ord-24fd76f526034765a26879c8fccd789d
Source dataset
uspto-grants-1992_07
Patent number
US05128335

Reaction notes

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