100 ml of diethyl ether, 40.2 g (0.3 mol) of vinylbenzylalcohol (synthesized by the method described in "Polymer", 14 330 (1973) from chloromethylstyrene (meta: para=about 6: about 4); b.p.=69° to 73° C./0.4 mm Hg), 30.3 g (0.3 mol) of triethylamine, and 0.5 g of 2,6-di-tbutylphenol were charged into a 300-ml three-necked flask equipped with a stirrer, a reflux condenser, and a calcium chloride tube, and the mixture was then cooled with ice-water. 109.4 g (0.3 mol) of the 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-n-heptanoic acid chloride synthesized above was cooled with ice and was added to the mixture dropwise, with stirring. Next the mixture was stirred for 2 hours at room temperature, after which it was stirred for 1 hour under reflux. Then, after cooling, the deposited triethylamine hydrochloride was filtered off, the filtrate was washed twice with water, then with an aqueous sodium carbonate solution, and then it was dried over anhydrous sodium carbonate. Distillation was carried out twice to purify the dried filtrate, thus giving 61.0 g (yield: 44.0%; b.p.: 106 to 116° C./0.9 mm Hg; d: 1.47) of 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-n-heptanoic acid vinylbenzyl ester.
