Bromobenzene → 2-bromo-5,6,8,9-tetrahydro-5,5,9,9-tetramethyl-7H-benzocyclohepten-7-one

HRID 981802

Reaction equation

HRID 981802 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:8][C:9](=[CH:11][C:12](=[O:17])[CH:13]=[C:14]([CH3:16])[CH3:15])[CH3:10].[Cl-].[Cl-].[Cl-].[Al+3]>C(=S)=S>[Br:1][C:2]1[CH:7]=[CH:6][C:5]2[C:14]([CH3:16])([CH3:15])[CH2:13][C:12](=[O:17])[CH2:11][C:9]([CH3:10])([CH3:8])[C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 7961BromobenzeneHCID 10438PhoroneHCID 6451240Aluminum(III) Chloride

Product 1

HCID 200710292-bromo-5,6,8,9-tetrahydro-5,5,9,9-tetramethyl-7H-benzocyclohepten-7-one

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

47.1 g of bromobenzene and 37.8 g of phorone are stirred at room temperature for 48 hours in the presence of 40 g of aluminum trichloride in 600 ml of carbon disulfide. The reaction mixture is then poured on to ice, extracted with diethyl ether. The extract is washed with water, dried and evaporated. After chromatography on silica gel with petroleum ether (low-boiling) and ethyl acetate (9:1) and recrystallization from hexane, there is obtained 2-bromo-5,6,8,9-tetrahydro-5,5,9,9-tetramethyl-7H-benzocyclohepten-7-one of m.p. 104°-105°.

Workup

  1. additionThe reaction mixture is then poured on to ice
  2. extractionextracted with diethyl ether
  3. washThe extract is washed with water
  4. customdried
  5. customevaporated
  6. customAfter chromatography on silica gel with petroleum ether (low-boiling) and ethyl acetate (9:1) and recrystallization from hexane

Sources & evidence

ORD record
ord-e0cd123ba4f94544bb7cbe6331cf05fa
Source dataset
uspto-grants-1991_02
Patent number
US04992574

Linked notes

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