To a solution of 10.0 g. (0.04 moles) of 7,15-diazadispiro [5,1,5,3] hexadecane-14,16-dione in 150 ml of anhydrous methanol in a 500 ml flask was added 2.6 g. of 86% KOH (0.04 moles) and the mixture was shaken until solution was obtained. The reaction mixture was then evaporated to dryness under reduced pressure. The residue was transferred to a 300 ml 3-necked flask equipped with a stirrer, thermometer, condenser with drying tube, dropping funnel and nitrogen inlet with the aid of a small amount of dry DMF. To the potassium imide salt, under a nitrogen atmosphere, was added 150 ml of dry DMF. To the stirred solution was added dropwise a solution of 13.3 g. (0.04 moles) of n-octadecyl bromide in 50 ml of DMF. The reaction mixture was heated slowly to 75° C and held at that temperature for 3 hours. The reaction mixture was cooled and allowed to stand at room temperature overnight. The reaction mixture was then taken up in 500 ml ether, the ether solution washed well with water, dried over anhydrous Na2SO4 and evaporated under reduced pressure. The residue, which crystallized on standing, was recrystallized from methanol yielding 14.3 g. of white needles as the product, m.p. 39°-40° C.
