Sulfuric Acid → 2,2,4,4,7-Pentamethyl-chroman

HRID 862264Notes

Reaction equation

HRID 862264 reaction equation
[CH3:1][C:2]([C:9]1[CH:14]=[CH:13][C:12]([CH3:15])=[CH:11][C:10]=1[OH:16])([CH3:8])[CH2:3][C:4]([CH3:7])(O)[CH3:5].S(=O)(=O)(O)O>>[CH3:7][C:4]1([CH3:5])[CH2:3][C:2]([CH3:1])([CH3:8])[C:9]2[C:10](=[CH:11][C:12]([CH3:15])=[CH:13][CH:14]=2)[O:16]1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 156611222-(1,1,3-Trimethyl-3-hydroxybutyl) 5-methyl-phenol2×

Product 1

HCID 156611242,2,4,4,7-Pentamethyl-chroman

Procedure

To 2.16 g (11.7 mmol) of 2-(1,1,3-trimethyl-3-hydroxybutyl) 5-methyl-phenol (Compound 88) was added under nitrogen 50 ml of 20% aqueous sulfuric acid. The reaction mixture was heated at reflux for 13 h and then cooled. The organic layer was separated and the aqueous layer was extracted with ether. The organic extracts were combined and washed successively with water, saturated NaHCO3 solution, water again and saturated NaCl solution and then dried (MgSO4). The solvent was removed in vacuo to give the title compound as a yellow oil. PMR (CDCl3): & 1.32 (6H, s), 1.34 (6H, s), 1.81 (2H, s), 2.26 (3H, s), 6.63 (1H, s), 6.72 (1H, d, J~7.9 Hz), 7.15 (1H, d, J~7.9 Hz).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 13 h
  3. temperaturecooled
  4. customThe organic layer was separated
  5. extractionthe aqueous layer was extracted with ether
  6. washwashed successively with water, saturated NaHCO3 solution, water again
  7. dry with materialsaturated NaCl solution and then dried (MgSO4)
  8. customThe solvent was removed in vacuo

Sources & evidence

ORD record
ord-2e272c639f9b43c6b805b0870d1ff1c7
Source dataset
uspto-grants-1998_02
Patent number
US05717094

Reaction notes

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