Bromine → 7-Bromo-4,4-dimethyl-1,2,3,4-tetrahydronaphthalen-1-one

HRID 1955510Notes

Reaction equation

HRID 1955510 reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].[CH3:5][C:6]1([CH3:17])[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:9](=[O:16])[CH2:8][CH2:7]1.[Br:18]Br>C(Cl)Cl>[CH3:5][C:6]1([CH3:17])[C:15]2[C:10](=[CH:11][C:12]([Br:18])=[CH:13][CH:14]=2)[C:9](=[O:16])[CH2:8][CH2:7]1

Participants

5

Reactant 3

HCID 24408BromineHCID 2365474,4-Dimethyl-3,4-dihydro-2H-naphthalen-1-oneHCID 6451240Aluminum(III) Chloride

Product 1

HCID 107533577-Bromo-4,4-dimethyl-1,2,3,4-tetrahydronaphthalen-1-oneYield 80%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A 100 ml three-necked flask, fitted with an efficient reflux condenser and drying tube, and addition funnel, was charged with a mixture of AlCl3 9.5g (71.4 mmol) and 3 ml of CH2Cl2. The 3,4-dihydro-4,4-dimethyl-1(2H)-naphthalenone (5.0 g, 28.7 mmol), was added dropwise with stirring (Caution: Exothermic Reaction|) to the mixture at room temperature. Bromine, 5.5 g (34.5 mmol), was then added very slowly, and the resulting mixture stirred for 2 hours at room temperature. (Note: if stirring stops, the mixture can be warmed to 70° C. until stirring resumes.) The reaction was then quenched by the slow addition of ice-cold 6M HCl. The mixture was extracted with Et2O and the combined organic layers washed with water, saturated aqueous NaHCO3, and saturated NaCl, before being dried over MgSO4. Removal of the solvent under reduced pressure, and distillation of the residue afforded 5.8 g (80%) of the product as a pale-yellow oil which solidified on standing, bp: 140° C./0.4 mm Hg. 1H NMR (CDCl3): δ8.11 (1H, d, J=3.0 Hz), 7.61 (1H, dd, J=3.0, 9.0 Hz), 7.31 (1H, d, J=9.0 Hz), 2.72 (2H, t, J=6.0 Hz), 2.01 (2H, t, J=6.0 Hz), 1.28 (6H, s).

Workup

  1. customA 100 ml three-necked flask, fitted with an efficient reflux condenser
  2. customdrying
  3. additiontube, and addition funnel
  4. stirringthe resulting mixture stirred for 2 hours at room temperature
  5. stirring(Note: if stirring stops
  6. temperaturethe mixture can be warmed to 70° C.
  7. stirringuntil stirring resumes
  8. custom) The reaction was then quenched by the slow addition of ice-cold 6M HCl
  9. extractionThe mixture was extracted with Et2O
  10. washthe combined organic layers washed with water, saturated aqueous NaHCO3, and saturated NaCl
  11. dry with materialbefore being dried over MgSO4
  12. customRemoval of the solvent
  13. distillationunder reduced pressure, and distillation of the residue

Sources & evidence

ORD record
ord-49df8d00a4ab496a8f20704d8d397671
Source dataset
uspto-grants-1998_07
Patent number
US05776699

Reaction notes

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