Iodine → 4-Iodo-2-methylphenol

HRID 1288488Notes

Reaction equation

HRID 1288488 reaction equation
[I:1]I.P([O:9][CH3:10])(OC)(OC)=O.[CH3:11][CH2:12][CH2:13][CH2:14][CH2:15][CH3:16]>O>[I:1][C:13]1[CH:14]=[C:15]([CH3:16])[C:10]([OH:9])=[CH:11][CH:12]=1

Participants

5

Reactant 3

HCID 807Iodine4×HCID 8058Hexane2×HCID 10541Trimethyl Phosphate

Product 1

HCID 1437134-Iodo-2-methylphenol

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

0-Cresol, 0.023 ml, iodine, 3 g, and 25 ml of trimethyl phosphate were held at 87° C under nitrogen for 12 hours with stirring. The iodine color having disappeared, 2.9 g more of iodine (total iodine 0.023 mol) was added and held 12 hours again. The iodine was gone but a brown color had developed. The mixture was poured into water and extracted with hexane. Three layers formed: the hexane layer containing the product, a dark viscous oil at interface of hexane, and water (which was a phosphate ester of product) the aqueous layer. The hexane layer was separated, dried and evaporated. The residue, 5 g, contained about 60% of the desired product (GLC, RT=108 sec. on 6 ft. SE 30 column at 150° and 40 ml of He/min. flow) and 40% trimethyl phosphate (40%, RT=60 sec.). There were indications of less than 1% 6-iodo-2 -cresol (RT=112 sec.) and about 1% 4,6-diiodo-2-cresol (RT=180 sec.). This crude mixture was warmed on a steam-bath with 8% aqueous sodium hydroxide, cooled, acidified, and the solid obtained filtered and washed. The same treatment was given to the heavy oil insoluble in hexane. The crude weight of 4-iodo-2-cresol obtained in this way were 3.5 g, 65% and 0.35 g, 6%, respectively. Recrystallization of first fraction gave shiny, beige-colored needles, mp 66.5°-68° (colorless melt), 1.55 g, 29% reported (C. M. Suter, R. D. Shultz, J. Org. Chem., 16, 1117 (1951)) mp 64°-65°. The second crop from the filtrate combined and recrystallized with the 0.35 g fraction gave 1.1 g, 20%, of darker beige needles, mp 65°-67° (amber melt).

Workup

  1. extractionextracted with hexane
  2. customThree layers formed
  3. customThe hexane layer was separated
  4. customdried
  5. customevaporated
  6. customabout 60% of the desired product (GLC, RT=108 sec. on 6 ft. SE 30 column at 150° and 40 ml of He/min. flow) and 40% trimethyl phosphate (40%, RT=60 sec.)
  7. temperatureThis crude mixture was warmed on a steam-bath with 8% aqueous sodium hydroxide
  8. temperaturecooled
  9. customthe solid obtained
  10. filtrationfiltered
  11. washwashed

Sources & evidence

ORD record
ord-4529b1fd24f545ba9a53d5683960372a
Source dataset
uspto-grants-1976_10
Patent number
US03988369

Reaction notes

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