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

HRID 1979889Notes

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

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 aluminium 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%+, exhibiting the expected spectral data.

Workup

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

Sources & evidence

ORD record: ord-b9997dad5a854e73ace9843c82110182
Source dataset: uspto-grants-1984_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04483786

Reaction notes

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