Dimethyl Sulfoxide → 1-methyl-4-phenyl-1H-imidazole

HRID 419733Notes

Reaction equation

HRID 419733 reaction equation
CS(C)=O.[OH-].[K+].[C:7]1([C:13]2[NH:17][CH:16]=[N:15][CH:14]=2)[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1.[CH3:18]I>O>[CH3:18][N:15]1[CH:14]=[C:13]([C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][CH:12]=2)[N:17]=[CH:16]1

Participants

6

Reactant 4

HCID 679Dimethyl SulfoxideHCID 6328Methyl iodideHCID 14797Potassium HydroxideHCID 695904-Phenylimidazole

Product 1

HCID 27487821-methyl-4-phenyl-1H-imidazoleYield 77.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Add 20 mL dimethyl sulfoxide (35 mL; 492.74 mmoles) to powdered potassium hydroxide (20.81 mmoles; 1.17 g). Add 5-phenyl-1H-imidazole (13.87 mmoles; 2.00 g) at room temperature and solid quickly dissolves giving an orange solution. After stirring 5 min add methyl iodide (15.26 mmoles; 950.36 μL) in one portion. Stir 4h at room temp. Dilute with water and extract with ethyl acetate (2×), then wash the organics with saturated aq. sodium chloride/water (2×) solution, dry over MgSO4, filter, evaporate to give 1.71 g yellow solid. Purify the crude by using ISCO chromatography over a biotage 40M column eluting with a gradient of 0.5% MeOH/DCM to 5% MeOH/DCM at a flow rate of 40 mL/min. Dry product fractions to give 1.43 g (65% yield) off-white solid. (7% of undesired regioisomer) MS (ES): (m/z)=159.0 [M+H].

Workup

  1. customgiving an orange solution
  2. extractionextract with ethyl acetate (2×)
  3. washwash the organics with saturated aq. sodium chloride/water (2×) solution
  4. dry with materialdry over MgSO4
  5. filtrationfilter
  6. customevaporate

Sources & evidence

ORD record
ord-995249150b8b4bf5aafe9bfe3596472e
Source dataset
uspto-grants-2012_01
Patent number
US08093383B2

Reaction notes

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