2-Bromotoluene → 6-Bromo-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthalene

HRID 1836859Notes

Reaction equation

HRID 1836859 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH3:8].Cl[C:10]([CH3:18])([CH2:12][CH2:13][C:14](Cl)([CH3:16])[CH3:15])[CH3:11].[Cl-].[Al+3].[Cl-].[Cl-]>ClCCl.CCCCCC.Cl>[Br:1][C:2]1[C:3]([CH3:8])=[CH:4][C:5]2[C:14]([CH3:16])([CH3:15])[CH2:13][CH2:12][C:10]([CH3:18])([CH3:11])[C:6]=2[CH:7]=1

Participants

7

Reactant 3

HCID 72362-BromotolueneHCID 80360Hexane, 2,5-dichloro-2,5-dimethyl-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 100393466-Bromo-1,1,4,4,7-pentamethyl-1,2,3,4-tetrahydronaphthaleneYield 87.3%

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 6344DichloromethaneSolventHCID 8058HexaneSolvent

Procedure

To a solution of 20 g (117 mmol) of 2-bromotoluene and 14.4 g (97.4 mmol) of 2,5-dichloro-2,5-dimethylhexane in 100 mL of dichloromethane was added 1.56 g (16.9 mmol) of aluminum chloride and the mixture heated at reflux. After 16 hours, the mixture was cooled to room temperature, diluted with 150 mL of hexane and 100 mL of 1 N HCl was added. The organic layer was separated and the aqueous layer was extracted with hexane. The combined organic layers were washed with saturated NaCl solution, dried over sodium sulfate and concentrated under reduced pressure. The product was purified by filtration through a pad of silica gel with elution with hexane and afforded 23.9 g (87%) of 2-bromo-3-methyl-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene as a solid. (m.p.: 81.1-85° C.).

Workup

  1. temperaturethe mixture heated
  2. temperatureat reflux
  3. additionwas added
  4. customThe organic layer was separated
  5. extractionthe aqueous layer was extracted with hexane
  6. washThe combined organic layers were washed with saturated NaCl solution
  7. dry with materialdried over sodium sulfate
  8. concentrationconcentrated under reduced pressure
  9. filtrationThe product was purified by filtration through a pad of silica gel with elution with hexane

Sources & evidence

ORD record
ord-5298263c09f843c88e4459ee3532ee0b
Source dataset
uspto-grants-2004_08
Patent number
US06777418B2

Reaction notes

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