[Sb](Cl)(Cl)(Cl)(Cl)Cl.[F:7][C:8]([F:22])([C:18]([F:21])([F:20])[F:19])[C:9]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)([F:11])[F:10].[Br:23]Br.ClCl.S(=O)(O)[O-].[Na+]>O>[Br:23][C:14]1[CH:13]=[C:12]([C:9]([F:11])([F:10])[C:8]([F:22])([F:7])[C:18]([F:19])([F:20])[F:21])[CH:17]=[CH:16][CH:15]=1First meta-bromo(heptafluoropropyl)benzene is prepared as follows. 12 g (0.04 mole) of antimony pentachloride are added to 389 g (1.58 mole) of heptafluoropropylbenzene and then, with intensive stirring, 41 ml (0.79 mole) of bromine are added in drops within an hour with simultaneously cooling the reaction mixture on a water bath. The temperature of the reaction mixture is maintained at 26° C maximum. After adding all the bromine, the reaction mixture is given another stirring for 15 minutes. In the course of the entire bromination reaction, dry chlorine is passed into the reaction mixture at a rate of 3 liters per hour. On completion of the reaction, for binding the unreacted bromine, the reaction mixture is poured into 500 ml of water containing 25 ml of saturated solution of sodium bisulphite. The reaction product is distilled with steam, neutralized with a 5 percent solution of sodium hydroxide dried over calcined calcium chloride, and rectified. The yield of meta-bromo(heptafluoropropyl)benzene is 447.2 g (87 percent of theory).
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