Sulfuric Acid → Phenol, 4-(1,1-dimethylethyl)-2,5-dimethyl-

HRID 2297082Notes

Reaction equation

HRID 2297082 reaction equation
[C:1]1([OH:9])[C:2]([CH3:8])=[CH:3][CH:4]=[C:5]([CH3:7])[CH:6]=1.S(=O)(=O)(O)O.[CH3:15][C:16](=[CH2:18])[CH3:17]>O.C([O-])(O)=O.[Na+]>[C:16]([C:4]1[CH:3]=[C:2]([CH3:8])[C:1]([OH:9])=[CH:6][C:5]=1[CH3:7])([CH3:18])([CH3:17])[CH3:15]

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 72672,5-DimethylphenolHCID 8255Isobutylene

Product 1

HCID 87249Phenol, 4-(1,1-dimethylethyl)-2,5-dimethyl-Yield 49%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 516892Sodium BicarbonateSolvent

Procedure

2,5-Xylenol (90 g, 0.73 mol) was melted at 80° C., 1 mL of concentrated sulfuric acid was added, and the mixture was heated at 90° C. while isobutylene gas was introduced subsurface over 4 hours. The reaction appeared to stall at about 80% conversion. The reaction mass was diluted with water and neutralized with NaHCO3, and some starting xylenol was removed by steam-distillation. Since the steam-distillation did not completely remove the starting material, the residue was dissolved in hot hexanes, separated from the aqueous phase, and cooled in an ice-bath. The precipitated product was filtered and washed with cold hexanes to give 64 g (49%) of 4-t-Butyl-2,5-xylenol; lit.(Stevens, Ind. Eng. Chem. 1943, 655; Parc, Rev. Inst. Fr. Pet. 1960, 680) mp 70-72° C. 1H-NMR (CDCl3) δ 1.37, (s, 9H), 2.20 (s, 3H), 2.43 (s, 3H), 4.85 (s, 1H), 6.53 (s, 1H), 7.08 (s, 1H).

Workup

  1. additionwas added
  2. additionwas introduced subsurface over 4 hours
  3. customsome starting xylenol was removed by steam-distillation
  4. distillationSince the steam-distillation
  5. customdid not completely remove the starting material
  6. dissolutionthe residue was dissolved in hot hexanes
  7. customseparated from the aqueous phase
  8. temperaturecooled in an ice-bath
  9. filtrationThe precipitated product was filtered
  10. washwashed with cold hexanes

Sources & evidence

ORD record
ord-8041c770dec248af8ff13544927ee3ac
Source dataset
uspto-grants-2002_12
Patent number
US06489517B1

Reaction notes

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