Patent ID: 6118033
Filing Date: 2000-09-12
Classification: C07C

Abstract:
An improved process for the continuous preparation of 1,1,1,2,3,3,3-heptafluoropropane from HF and hexafluoropropene, allowing achievement of at least 99.99% conversion of the hexafluoropropene, wherein(a) HF and hexafluoropropene are converted in a first zone in the presence of at least one liquid hydrofluoride of an organonitrogen base corresponding to formula (I)[B.times.nHF] (I),in which B represents an organonitrogen base and n represents an integer or a fraction.ltoreq.4, under a pressure of p1=1.3 to 10 bar,(b) the liquid reaction mixture obtained in (a) is transferred to a second zone under a pressure p2, in which p2.gtoreq.1 bar and the pressure difference p1-p2.gtoreq.0.3 bar,(c) the resulting heptafluoropropane is evaporated and isolated from the liquid reaction mixture, and(d) the remaining liquid reaction mixture is then transferred, after addition of hexafluoropropene and HF back into the first zone.