4,4,5,5-Tetrachloro-2,2-difluoro-1,3-dioxolane → 1,3-Dioxole, 4,5-dichloro-2,2-difluoro-

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Reaction Steps

A 300 mL, 3-neck glass flask equipped with magnetic stirrer, thermometer, Vigreux column with a water condenser to receiver, trap to a nitrogen tee and bubbler was charged with 1-propanol, 175 mL; zinc dust, 59.3 g; zinc chloride, 2.0 g. After heating to reflux, the 2,2-difluoro-4,4,5,5-tetrachloro-1,3-dioxolane (4j), 74.3 g, was added by syringe pump at 0.33 mL/minute. The addition was complete in 148 minutes. Distillation was begun 40 minutes after the start of the addition and continued for 6 hours until 72 mL of distillate was collected. The product was 98.7% pure desired dioxole, (3j), at 100% conversion of the dioxolane; the distillate which contained some propanol was redistilled through a 0.51 m spinning band column to separate the dioxole, (3j), b.p. 64°-65° C., at a purity of 98.6%. A 3.66 m×0.0064 m diameter 30% "Krytox" perfluoroether (Du Pont Co.) column at 60° C. was used in the analysis. The infrared spectrum was consistent with the structure.

Provenance & Evidence