Chlorine → 1-Chloro-1,1,3,3,3-pentafluoropropane

Temperature

0 °C

The reactor described above was cooled and maintained at about 0° C. during the photochlorination reaction. Initially, the reactor was purged of air using nitrogen. Chlorine gas was then introduced to displace the nitrogen. Thereafter, 335 g (2.5 mol) of CF3CH2CHF2 (HFC-245fa) was charged to the reactor. A total of 208 g (2.9 mol) of chlorine gas was bubbled into the CF3CH2CHF2 over a period of about 24 hours while the reactants were being irradiated. At the end of the 24 hour period, GC analysis indicated a 96% conversion of HFC-245fa (retention time 1.9 min) to the desired product HCFC-235fa (retention time 2.1 min). The reaction mixture was washed with 100 mL of a cooled (about 2° C.) solution of aqueous sodium bisulfite (10 wt. %) and distilled (boiling point=26-28° C.) to afford 383 g CF3CH2CF2Cl (yield, 91%). Absent cooling of the wash solution, loss of product by vaporization has been observed due to a slight exotherm during the washing step. No multichlorinated products were detected.

1. temperatureThe reactor described above was cooled
2. customInitially, the reactor was purged of air
3. additionChlorine gas was then introduced
4. customwere being irradiated
5. customAt the end of the 24 hour period, GC analysis

ORD record

ord-9c1e346ee53e47628512433d4908f53f

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06551469B1