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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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 percent pellets, 80.Og, 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 percent yield).

Herkunft & Nachweise