M-Cresol → 3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-1-ol

HRID 1632450Notes

Reaction equation

HRID 1632450 reaction equation
[CH3:1][C:2](Cl)([CH2:4][CH2:5][C:6]([CH3:9])(Cl)[CH3:7])[CH3:3].[CH:11]1[C:16]([OH:17])=[CH:15][CH:14]=[CH:13][C:12]=1[CH3:18]>[Cl-].[Al+3].[Cl-].[Cl-].C(Cl)CCl>[OH:17][C:16]1[C:15]2[C:6]([CH3:9])([CH3:7])[CH2:5][CH2:4][C:2]([CH3:3])([CH3:1])[C:14]=2[CH:13]=[C:12]([CH3:18])[CH:11]=1

Participants

5

Reactant 2

HCID 342M-CresolHCID 80360Hexane, 2,5-dichloro-2,5-dimethyl-

Product 1

HCID 216784833,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-1-olYield 78.3%

Reagents, catalysts & solvents 2

HCID 6451240Aluminum(III) ChlorideCatalystHCID 111,2-DichloroethaneSolvent

Conditions

Temperature
95 °C

Procedure

2,5-Dimethyl-2,5-dichlorohexane (183 g, 1 mol) was stirred with m-cresol (129.6 g, 1.2 mol) and aluminum chloride (4 g) was added in one portion. The mixture was heated at 95° C., with stirring for 1.5 h, after which ethylene dichloride (100 mL) was added and then the heating was continued. After 1 h the mixture was cooled to 20° C. and poured onto an ice-water/hydrochloric acid mixture (150 mL, 10% HCl solution). The mixture was then extracted with toluene (500 mL). The organic layer was separated, washed with brine (3×50 mL) and dried (Na2SO4). The solvent was removed by distillation and the residue was crystallized from a hexane/benzene solvent mixture to give 1-hydroxy-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene (171 g), mp 133°-134° C., GLC purity 99%+. 1H-NMR (CDCl3) δ6.82 (1H, broad s), 6.35 (1H, d, J= 1.4 Hz), 4.72 (1H, s), 2.30 (3H, s), 1.71 (4H, m), 1.49 (6H, s), 1.34 (6H, s). 13C-NMR (CDCl3) δ154.2 (1C, s), 147.8 (1C, s), 135.7 (1C, s), 128.0 (1C, s), 120.2 (1C, d), 114.6 (1C, d), 37.9 (1C, t), 35.2 (1C, t), 34.6 (1C, s), 33.7 (1C, s), 32.0 (2C, q), 28.5 (2C, q), 20.8 (1C, q). IR (KBr) 3,503 cm-, MS (m/e) 218 (M+, 24.7), 203 (100.0), 161 (55.1), 147 (23.9), 57 (10.9).

Workup

  1. additionwas added in one portion
  2. temperatureAfter 1 h the mixture was cooled to 20° C.
  3. extractionThe mixture was then extracted with toluene (500 mL)
  4. customThe organic layer was separated
  5. washwashed with brine (3×50 mL)
  6. dry with materialdried (Na2SO4)
  7. customThe solvent was removed by distillation
  8. customthe residue was crystallized from a hexane/benzene solvent mixture

Sources & evidence

ORD record
ord-41ba87feb3594e77bcbfbf2644664161
Source dataset
uspto-grants-1984_10
Patent number
US04476040

Reaction notes

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