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

HRID 727876Notes

Reaction equation

HRID 727876 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 45) 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) The solvent
  8. customwas removed in vacuo

Sources & evidence

ORD record
ord-ac106b393626488bb09b24ded90ee558
Source dataset
uspto-grants-1991_09
Patent number
US05045551

Reaction notes

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