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

Participants

Reaction Steps

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.

Provenance & Evidence