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

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.

1. customA 300 mL, 3-neck glass flask equipped with magnetic stirrer
2. temperatureAfter heating
3. temperatureto reflux
4. additionThe addition
5. distillationDistillation
6. waitwas begun 40 minutes
7. additionafter the start of the addition
8. waitcontinued for 6 hours until 72 mL of distillate
9. customwas collected
10. distillationwas redistilled through a 0.51 m
11. customto separate the dioxole, (3j), b.p. 64°-65° C.
12. customat 60° C.

ORD record

ord-d8893cde457547b8954650d70bbe6c7d

Source dataset

uspto-grants-1985_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04535175