1: 1,1,1,3,4,4,5,5,5-nonafluoro-2-trifluoromethyl-2-pentene With cesium fluoride in N,N-dimethyl-formamide T=45°C; 36 h; 2: 1-(iodomethyl)-4-bromobenzene in N,N-dimethyl-formamide T=65°C; 14 h; Further stages.;

1: tetrahydrothiophene 1,1-dioxide / 144 h / 65 °C 2: Br2, FeBr3 / Heating View Scheme

1: tetrahydrothiophene 1,1-dioxide / 144 h / 65 °C 2: Br2, FeBr3 / Heating View Scheme

in sulfolane T=65°C; 144 h; Yield given;

iron tribromide; bromine Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;