In a three necked 1 liter round bottom reaction vessel equipped with a mechanical stirrer and reflux condenser were placed 97.5 g (0.3 mol) of the compound of Example 8 and 200 ml of hexamethylphosphoric-triamide. The mixture was heating with stirring under nitrogen at 80°-90° C. till the solid dissolved. To this solution was added with stirring 252 g (3 mol) sodium bicarbonate powder. Over a period of about 0.5 hour 29.4 ml of an 80% w/w solution of propargyl bromide in toluene (0.315 mol propargyl bromide) were added with stirring. After the reaction had run for 21 hours an additional 4 ml of the propargyl bromide solution in toluene (0.043 mol propargyl bromide) was added and the reaction continued for an additional 68 hours. The reaction mixture was then cooled and diluted with 1 liter of ethyl acetate. The mixture was transferred to a separatory funnel, cross-washed with water/brine, then with a 2 molor aqueous citric acid and again with brine. The organic layer was dried over anhydrous magnesium sulfate, clarified and evaporated to yield 108 g of a dark oil which was purified by chromatography over silica gel to yield a solid which was recrystallized from ethyl acetate/hexane. M.p. 168°-170° C.
