Water → 1-(5-Methyl-2-propyl-1H-imidazol-4-yl)ethan-1-one

HRID 543875Notes

Reaction equation

HRID 543875 reaction equation
[CH3:1][CH:2]([C:4]1[N:5]=[C:6]([CH2:10][CH2:11][CH3:12])[NH:7][C:8]=1[CH3:9])[OH:3].CC(C)=O.OS(O)(=O)=O.O=[Cr](=O)=O.O.CC(O)C>CC(C)=O>[CH2:10]([C:6]1[NH:7][C:8]([CH3:9])=[C:4]([C:2]([CH3:1])=[O:3])[N:5]=1)[CH2:11][CH3:12]

Participants

6

Reactant 4

HCID 962WaterHCID 3776IsopropanolHCID 13314351HCID 13314351, compoundHCID 131709961Jones' reagent

Product 1

HCID 131770121-(5-Methyl-2-propyl-1H-imidazol-4-yl)ethan-1-one

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A suspension of 86.2 g. of α,5-dimethyl-2-n-propyl-4-imidazolemethanol in 2.16 liters of acetone is stirred in an ice bath and 430.9 ml. of Jones' reagent (120 g. of chromium trioxide, 257 ml. of water, 106.7 ml. of concentrated sulfuric acid, combined and diluted to 461.7 ml. with water) is dripped in at 20°-30° C. internal temperature over a period of one hour. Stirring is continued for 30 miuntes after the addition is complete, then 256 ml. of water were added. The reaction is then cooled in an ice bath and 256 ml. of 2-propanol are slowly added, maintaining the internal temperature at 20°-30° C. Stirring is continued for one hour, giving a suspension of solid and liquid. The liquid is decanted, concentrated to remove most of the acetone, and the aqueous residue is recombined with the solid. This mixutre is basified with concentrated aqueous potassium bicarbonate and an additional amount of solid potassium bicarbonate. The mixture is extracted with three 300 ml. portions of ethyl acetate. The extracts are combined, back washed with 100 ml. of saturated aqueous potassium bicarbonate dried over sodium sulfate and the solvent is removed in vacuo, giving the desired ketone which crystallizes on standing.

Workup

  1. additionA suspension of 86.2 g
  2. additionafter the addition
  3. temperatureThe reaction is then cooled in an ice bath
  4. temperaturemaintaining the internal temperature at 20°-30° C
  5. stirringStirring
  6. customgiving
  7. additiona suspension of solid and liquid
  8. customThe liquid is decanted
  9. concentrationconcentrated
  10. customto remove most of the acetone
  11. extractionThe mixture is extracted with three 300 ml
  12. washback washed with 100 ml
  13. dry with materialof saturated aqueous potassium bicarbonate dried over sodium sulfate
  14. customthe solvent is removed in vacuo

Sources & evidence

ORD record
ord-99b9eb624174410b8f92c86b9358a39e
Source dataset
uspto-grants-1984_05
Patent number
US04447603

Reaction notes

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