Carbon Dioxide → 2,2-Bis(trifluoromethyl)-4-hydroxymethyl-1,3-dioxolane

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

118 Grams glycerol carbonate (1 mole) is placed in a 500 ml three neck flask, fitted with a thermometer, magnetic stirrer, gas-inlet tube, and a condenser cooled with a dry ice-isopropyl alcohol bath. Hexafluoroacetone gas is added to the vigorously stirred glycerol carbonate at 27° to 60° C. until 142 grams (0.85 moles) has been absorbed. The dry ice condenser is now replaced by a water condenser which is connected to a dry ice trap so that hexafluoroacetone which escapes during reaction may be condensed. The temperature is raised slowly to about 118° C. at which point CO2 evolution begins. The temperature is allowed to rise to 148° C. during a 40 hour reaction period. The resulting product is mixed with water (50 ml) and the organic layer separated and diluted with chloroform. The chloroform solution is washed several times with water and 5% NaHCO3 solution. Vacuum stripping gives crude 2,2-bis(trifluoromethyl)-4-hydroxymethyl-1,3-dioxolane. This is distilled at 78° - 80° C./25 mm Hg and the yield of pure product is 92%, based on utilized hexafluoroacetone. The twice distilled product has a refractive index of 1.35046 (20° C.) and upon analysis contained 47.19% fluorine, 30.02% carbon, and 2.22% hydrogen.

Herkunft & Nachweise