A solution of 664 g of sodium hydroxide in 996 ml of water is added to a solution, stirred at room temperature, of 87.5 g of crude 4,5,10,11-tetrahydro-1H-dibenzo[a,d]cycloheptene-5-ethanol, 103.7 g of p-toluenesulfochloride and 7.2 g of benzyltriethylammonium chloride in 1440 ml of methylene chloride and the mixture is stirred at room temperature overnight. The mixture is treated with 2 l of ice-water and extracted with 3 l of methylene chloride. The organic extracts are washed neutral with water. The aqueous extracts remaining are subsequently back-extracted three times with 2 l of methylene chloride each time. The organic extracts are combined, dried over magnesium sulfate and evaporated. After four-fold recrystallization of the solid residue from toluene, there is obtained pure 2-(4,5,10,11-tetrahydro-1H-dibenzo[a,d]cyclohepten-5-yl)ethyl-p-toluenesulfonate of melting point 150°-151°.
