To a solution of 32 g piperonyl piperazine in 100 ml anhydrous toluene, 10 g sodium carbonate are added and 35.2 g benzhydryl chloride are added dropwise. The mixture is then heated to reflux for 7 hours with vigorous agitation. Then the mixture is cooled, the salt that has formed is filtered out and 100 ml water is added. The organic layer is extracted with several batches of 10% methane sulfonic acid. The acid extracts are combined and washed with ether then alkalized with sodium carbonate. The mixture is
extracted with several batches of chloroform and the combined chloroform
solutions are washed several times with water. After drying and solvent
evaporation, the crude base of 1-diphenylmethyl-4-piperonyl-piperazineis
isolated and the hydrochloride thereof is formed in acetone. After
recrystallization 22.5 g of the dihydrochloride are finally obtained. M.P.:
228°C, from methanol.
