GB1281822A - Improved fluorination process - Google Patents

Abstract

1281822 Fluorination process IMPERIAL SMELTING CORP (NSC) Ltd 9 Dec 1969 [16 Jan 1969 5 Sept 1969] 2592/69 and 44130/69 Heading C2C A continuous process for fluorinating organic compounds comprises simultaneously feeding fluorine gas and one or more organic compounds into a mechanically fluidized bed containing at least one solid inorganic metal fluoride capable of acting as a fluorinating agent by conversion to a lower valency fluoride. The exemplified fluoride is cobalt trifluoride, used in admixture with cobalt difluoride. The fluorine gas converts the difluoride to the trifluoride. The fluorine may be diluted with an inert gas or gases, for example nitrogen. The bed may contain one or more inert solids to act as heat carriers, and is fluidized by one or more impellers immersed therein. The product may be passed through a separator to remove cobalt fluoride dust and thereafter either (a) washed with water, preferably refrigerated, and the resulting liquid separated into aqueous hydrofluoric acid and the fluorination product, or (b) condensed and the condensate separated into anhydrous hydrofluoric acid and the fluorination product. In the latter case, the anhydrous hydrofluoric acid may be passed to an electrolytic cell to produce fluorine to be fed back to the reactor. Temperatures of 35- 450‹ C. are used if fully fluorinated products are required. Examples prepare (a) perfluoro-1- methyl-decalin from 1-methyl naphthalene, (b) perfluoro-1,3-dimethyl cyclohexane from mxylene, (c) perfluoro-n-hexane from n-hexane, and (d) per (chlorofluoro) cyclopentanes from hexachlorocyclopentadiene.