Dimethyl Sulfate → 1-Methyl-2-phenyl-1H-imidazole

HRID 264755Notes

Reaction equation

HRID 264755 reaction equation
[C:1]1([C:7]2[NH:8][CH:9]=[CH:10][N:11]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH:12]([N-]C(C)C)(C)C.[Li+].S(OC)(OC)(=O)=O.[Cl-].[NH4+]>O1CCCC1>[CH3:12][N:11]1[CH:10]=[CH:9][N:8]=[C:7]1[C:1]1[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

6

Reactant 4

HCID 6497Dimethyl SulfateHCID 25517Ammonium ChlorideHCID 695912-PhenylimidazoleHCID 2724682Lithium diisopropylamide

Product 1

HCID 770251-Methyl-2-phenyl-1H-imidazole

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 40 mL tetrahydrofuran containing 1.0 g of 2-phenylimidazole was cooled to 0° C. and 4 mL of 2M lithium diisopropylamide was added dropwise which resulted in the formation of a white suspension. The mixture was stirred for 10 min at 0° C. and then 0.7 mL of dimethyl sulfate was added. The reaction was allowed to stir at room temperature for an additional 30 min during which time the solution became homogeneous. Aqueous ammonium chloride was added and the tetrahydrofuran was removed by evaporation under reduced pressure. The aqueous phase was extracted with 2×100 mL aliquots of dichloromethane. The combined organic extracts were washed with dilute ammonium hydroxide and brine. The combined organic extracts were dried over anhydrous sodium sulfate and concentrated under reduced pressure to yield 1 g of 1-methyl-2-phenylimidazole which was used in the next step without further purification or characterization.

Workup

  1. customresulted in the formation of a white suspension
  2. stirringto stir at room temperature for an additional 30 min during which time the solution
  3. customthe tetrahydrofuran was removed by evaporation under reduced pressure
  4. extractionThe aqueous phase was extracted with 2×100 mL aliquots of dichloromethane
  5. washThe combined organic extracts were washed with dilute ammonium hydroxide and brine
  6. dry with materialThe combined organic extracts were dried over anhydrous sodium sulfate
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-94231464b4484e46a8346e00bbde6fdc
Source dataset
uspto-grants-1997_07
Patent number
US05646281

Reaction notes

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