Sulfuric Acid → 7-dimethylamino-9-phenyl-6,7-dihydro [5H] benzocycloheptene

HRID 372544Notes

Reaction equation

HRID 372544 reaction equation
[CH3:1][N:2]([CH3:21])[CH:3]1[CH2:9][CH2:8][C:7]2[CH:10]=[CH:11][CH:12]=[CH:13][C:6]=2[C:5]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)(O)[CH2:4]1.S(=O)(=O)(O)O.[OH-].[NH4+].[Cl-].[Na+]>O1CCOCC1>[CH3:1][N:2]([CH3:21])[CH:3]1[CH:4]=[C:5]([C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)[C:6]2[CH:13]=[CH:12][CH:11]=[CH:10][C:7]=2[CH2:8][CH2:9]1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 5234Sodium ChlorideHCID 14923Ammonium HydroxideHCID 542538337-dimethylamino-5-phenyl-5-hydroxy-6,7,8,9-tetrahydro [5H] benzocycloheptene

Product 1

HCID 30468657-dimethylamino-9-phenyl-6,7-dihydro [5H] benzocyclohepteneYield 74.2%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

A mixture of 29.1 g of 7-dimethylamino-5-phenyl-5-hydroxy-6,7,8,9-tetrahydro [5H] benzocycloheptene and 290 ml of dioxane was refluxed under an inert gas and then 60 ml of 18 N sulfuric acid were added thereto. The mixture was stirred for 3 minutes and after cooling, was poured over ice. The pH was adjusted above 10 by addition of concentrated ammonium hydroxide and the mixture was saturated with sodium chloride and was extracted with ethyl acetate. The organic extracts were washed with aqueous sodium chloride solution, were dried and evaporated to dryness. The residue was chromatographed over silica gel and was eluted with a 10-1 benzene-triethylamine mixture to obtain 20.2 g of 7-dimethylamino-9-phenyl-6,7-dihydro [5H] benzocycloheptene.

Workup

  1. temperaturewas refluxed under an inert gas
  2. temperatureafter cooling
  3. additionwas poured over ice
  4. extractionwas extracted with ethyl acetate
  5. washThe organic extracts were washed with aqueous sodium chloride solution
  6. customwere dried
  7. customevaporated to dryness
  8. customThe residue was chromatographed over silica gel
  9. washwas eluted with a 10-1 benzene-triethylamine mixture

Sources & evidence

ORD record
ord-f37cb0ed346a4a22a501aaa9d2b5ad5b
Source dataset
uspto-grants-1978_05
Patent number
US04091115

Reaction notes

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