Patent ID: 6919480

Claim:
A process for preparing a fluorinated acyl fluoride of formula (3) comprising, (i) reacting a compound of formula (1) having a fluorine content of 30 mass % or above with fluorine in a liquid phase to form a compound of formula (2); (ii) dissociating the ester bond in the compound of formula (2); (iii) irradiating a reaction system of (i) with ultraviolet light: wherein each of R A and R B , which may be the same or different, is a monovalent saturated hydrocarbon group, a halogenated monovalent saturated hydrocarbon group, a hetero atom-containing monovalent saturated hydrocarbon group or a halogenated (hetero atom-containing monovalent saturated hydrocarbon) group, each of R C and R D , which may be the same or different, is a hydrogen atom, a halogen atom, a monovalent saturated hydrocarbon group, a halogenated monovalent saturated hydrocarbon group, a hetero atom-containing monovalent saturated hydrocarbon group or a halogenated (hetero atom-containing monovalent saturated hydrocarbon) group, each of X 1 , X 2 , X 3 , X 4 , X 5 and X 6 , which may be the same or different, is a hydrogen atom or a fluorine atom, provided that at least one of R A , R B , R C , R D , X 1 , X 2 , X 3 , X 4 , X 5 and X 6 is a fluorine-containing group or a fluorine atom, R AF corresponds to R A , R BF corresponds to R B , R CF corresponds to R C , R DF corresponds to R D , and when R A , R B , R C and R D are hydrogen-containing groups, R AF R BF , R CF and R DF are groups derived respectively from R A , R B , R C and R D by replacing substantially all the hydrogen atoms by fluorine atoms, and when R A , R B , R C and R D are groups containing no hydrogen atoms, R AF , R BF , R CF and R DF are the same as R A , R B , R C and R D , respectively, the combination of R A and R B and the combination of R C and R D may form bivalent groups selected from bivalent saturated hydrocarbon groups, halogenated bivalent saturated hydrocarbon groups, hetero atom-containing bivalent saturated hydrocarbon groups and halogenated (hetero atom-containing bivalent saturated hydrocarbon) groups, respectively, the combination of R AF and R BF forms a bivalent group corresponding to a bivalent group formed by the combination of R A and R B , and the combination of R CF and R DF forms a bivalent group corresponding to a bivalent group formed by the combination of R C and R D , provided that when the combination of R A and R B and the combination of R C and R D form hydrogen-containing bivalent groups, the bivalent groups formed by the combination of R AF and R BF and the combination of R CF and R DF are groups derived from the hydrogen-containing bivalent groups by replacing substantially all the hydrogen atoms by fluorine atoms, and when the combination of R A and R B and the combination of R C and R D form bivalent groups containing no hydrogen atoms, the bivalent groups formed by the combination of R AF and R BF and the combination of R CF and R DF are the same as the bivalent groups containing no hydrogen atoms.