Hydrochloric Acid → 6,7-Dichloro-4-(4-chlorophenyl)-1,2-dihydronaphthalene

HRID 2164256Notes

Reaction equation

HRID 2164256 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[Cl:12])[C:8](=O)[CH2:7][CH2:6][CH2:5]2.[ClH:14].[C:15]1(C)[CH:20]=[CH:19][C:18](S(O)(=O)=O)=[CH:17][CH:16]=1>C(OCC)C.C1(C)C=CC=CC=1>[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[Cl:12])[C:8]([C:15]1[CH:20]=[CH:19][C:18]([Cl:14])=[CH:17][CH:16]=1)=[CH:7][CH2:6][CH2:5]2

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 6101p-Toluenesulfonic acidHCID 3086046,7-DICHLORO-1-TETRALONE

Product 1

HCID 204060666,7-Dichloro-4-(4-chlorophenyl)-1,2-dihydronaphthalene

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 3283Diethyl EtherSolvent

Procedure

Magnesium turnings (1.5 g.) and diethyl ether (30 ml.) were stirred while a solution of p-bromochlorobenzene (12 g.) in diethyl ether (100 ml.) was added to form the Grignard reagent. The solution was heated under reflux for 10 minutes, then a solution of 6,7-dichloro-1,2,3,4-tetrahydro-1-oxonaphthalene (9 g.) in diethyl ether (100 ml.) was added over 20 minutes, and the mixture was then heated under reflux for 30 minutes. The reaction mixture was cooled and acidified with 2N hydrochloric acid (50 ml.), and the ether layer was separated, dried, and evaporated to dryness leaving an oil. This residual oil was dissolved in toluene (300 ml.), toluene-p-sulphonic acid (0.5 g.) was added, and the solution was heated under reflux in an Dean and Stark apparatus for 2 hours, while 0.5 ml. of water was collected. The toluene was evaporated under reduced pressure and the residual oil was chromatographed on silica (Merck's Grade 7734) using petroleum ether (b.p. 60°-80° C.) as the eluant, to give 6,7-dichloro-1-(4-chlorophenyl)-3,4-dihydronaphthalene as a white crystalline solid, m.p. 106°-108° C.

Workup

  1. temperatureThe solution was heated
  2. temperatureunder reflux for 10 minutes
  3. temperaturethe mixture was then heated
  4. temperatureunder reflux for 30 minutes
  5. temperatureThe reaction mixture was cooled
  6. customthe ether layer was separated
  7. customdried
  8. customevaporated to dryness
  9. customleaving an oil
  10. temperaturethe solution was heated
  11. temperatureunder reflux in an Dean and Stark apparatus for 2 hours, while 0.5 ml
  12. customof water was collected
  13. customThe toluene was evaporated under reduced pressure
  14. customthe residual oil was chromatographed on silica (Merck's Grade 7734)

Sources & evidence

ORD record
ord-44f6a7443ded4ce28894d494df235c13
Source dataset
uspto-grants-1985_03
Patent number
US04503062

Reaction notes

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