Dimethyl Sulfoxide → 1,1,1-Tris(4-(2-bromotetrafluoroethoxy)phenyl)ethane

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Reaction Conditions

Reaction Steps

A 1 liter 5-necked round bottom flask is fitted with a mechanical stirrer, a Dean-Stark trap topped with a nitrogen padded reflux condenser, and a thermocouple attached to a temperature controller. A mixture of DMSO (450 ml), toluene (150 ml), and 1,1,1-tris(4'-hydroxyphenyl)ethane (55.1 g, 0.18 mole) is added to the flask under nitrogen purge. After stirring for 15 minutes under a vigorous nitrogen purge, potassium hydroxide (85% pellets, 80.0 g, 1.2 mole) is slowly added to the reaction flask. The mixture is then stirred at reflux for 48 hours with azeotropic removal of water. The resulting suspension is cooled to 35° C. in an ice bath and 1,2-dibromotetrafluoroethane (155 g, 0.60 mole) is added at a rate that maintains a temperature of 30°-35° C. When the addition is complete, the mixture is heated to 50° C. with continuous stirring for 3 hours. After filtration, the solvents are removed by heating under vacuum on a rotary evaporator. The brown residue is purified by column chromatography on neutral alumina using hexane as eluent to provide as product 1,1,1-tris(4'-[2"-bromotetrafluoroethoxy]phenyl)ethane (18.3 g, 0.022 mole, 12% yield).

Provenance & Evidence