Methyl iodide → 2-Iodo-5-methoxy-1,3-dimethylbenzene

HRID 1638423Notes

Reaction equation

HRID 1638423 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([OH:10])[CH:5]=[C:6]([CH3:9])[C:7]=1[I:8].[C:11](=O)([O-])[O-].[K+].[K+].CI>CC(C)=O>[CH3:11][O:10][C:4]1[CH:5]=[C:6]([CH3:9])[C:7]([I:8])=[C:2]([CH3:1])[CH:3]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 27362644-Iodo-3,5-dimethyl-phenol2×

Product 1

HCID 147206012-Iodo-5-methoxy-1,3-dimethylbenzene

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

O-Methyl-3,5-dimethyl-4-iodophenol was prepared by etherifying 3,5-dimethyl-4-iodophenol as follows: In a 1 l three-necked flask equipped with an overhead stirrer were placed 63.7 g (257 mmol) of 3,5-dimethyl-4-iodophenol, 70.9 g (513 mmol) potassium carbonate, 400 ml acetone and 47.5 ml (108 g, 760 mmol) methyl iodide. The reaction mixture was refluxed for 15 hours, cooled, the precipitate filtered and washed with acetone. The combined acetone washes were concentrated under reduced pressure, dissolved in methylene chloride, washed successively with 5% sodium hydroxide, saturated sodium bisulfite and water. After drying over magnesium sulfate and filtering, the solvent was removed under reduced pressure to afford a tan oil. Recrystallization from hot methanol with cooling to room temperature and then -78° C. afforded 58.2 g (86% yield) of white needles, mp 33°-34° C., which were identified as O-methyl-3,5-dimethy-4-iodophenol. 1H NMR analysis indicated: (δ, CDCl3) 6.56 (s, 2H), 3.67 (s, 3H) and 2.37 (s, 6H). Mass spectrum analysis indicated: (m/e) 262 (m+, 100%), 247, 219, 135 and 91.

Workup

  1. customIn a 1 l three-necked flask equipped with an overhead stirrer
  2. temperatureThe reaction mixture was refluxed for 15 hours
  3. temperaturecooled
  4. filtrationthe precipitate filtered
  5. washwashed with acetone
  6. concentrationThe combined acetone washes were concentrated under reduced pressure
  7. dissolutiondissolved in methylene chloride
  8. washwashed successively with 5% sodium hydroxide, saturated sodium bisulfite and water
  9. dry with materialAfter drying over magnesium sulfate
  10. filtrationfiltering
  11. customthe solvent was removed under reduced pressure
  12. customto afford a tan oil
  13. customRecrystallization from hot methanol

Sources & evidence

ORD record
ord-424cc2bd0a41493d92f400bedf773cae
Source dataset
uspto-grants-1989_11
Patent number
US04879398

Reaction notes

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