Benzene → 6-Bromo-1,1-dimethyl-4-p-tolyl-1,2-dihydronaphthalene

HRID 618019Notes

Reaction equation

HRID 618019 reaction equation
O[C:2]1([C:15]2[CH:20]=[CH:19][C:18]([CH3:21])=[CH:17][CH:16]=2)[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([Br:12])[CH:10]=2)[C:5]([CH3:14])([CH3:13])[CH2:4][CH2:3]1.C1C=CC=CC=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>CCOCC>[CH3:21][C:18]1[CH:17]=[CH:16][C:15]([C:2]2[C:11]3[C:6](=[CH:7][CH:8]=[C:9]([Br:12])[CH:10]=3)[C:5]([CH3:14])([CH3:13])[CH2:4][CH:3]=2)=[CH:20][CH:19]=1

Participants

5

Reactant 3

HCID 241BenzeneHCID 521998p-Toluenesulfonic acid monohydrateHCID 105454491,2,3,4-Tetrahydro-1-hydroxy-1-(4-methylphenyl)-4,4-dimethyl-7-bromonaphthalene2×

Product 1

HCID 106876226-Bromo-1,1-dimethyl-4-p-tolyl-1,2-dihydronaphthalene

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

A flask equipped with a Dean-Stark trap was charged with 3.4 g of (9.85 mmol) of 1,2,3,4-tetrahydro-1-hydroxy-1-(4-methylphenyl)-4,4-dimethyl-7-bromonaphthalene (Compound C) and 40 ml of benzene. A catalytic amount of p-toluenesulfonic acid monohydrate was added and the resulting solution heated to reflux for 2 hours. Upon cooling to room temperature, Et2O was added and the solution washed with H2O, saturated aqueous NaHCO3, and saturated aqueous NaCl then dried over MgSO4. Removal of the solvents under reduced pressure, and column chromatography (100% hexane/silica gel) afforded the title compound as a colorless solid. 1H NMR (CDCl3): δ 7.32 (1H, dd, J=2.1, 8.2 Hz), 7.21 (5H, m), 7.15 (1H, d, J=2.1 Hz), 5.98 (1H, t, J=4.7 Hz), 2.40 (3H, s), 2.32 (2H, d, J=4.7 Hz), 1.30 (6H, s).

Workup

  1. customA flask equipped with a Dean-Stark trap
  2. temperaturethe resulting solution heated
  3. temperatureto reflux for 2 hours
  4. washthe solution washed with H2O, saturated aqueous NaHCO3, and saturated aqueous NaCl
  5. dry with materialthen dried over MgSO4
  6. customRemoval of the solvents under reduced pressure, and column chromatography (100% hexane/silica gel)

Sources & evidence

ORD record
ord-6ac760f1b63e4e33b7490fc79e7779b2
Source dataset
uspto-grants-1999_09
Patent number
US05952345

Reaction notes

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