Patent ID: 7572942

Claim:
A process for the preparation of a compound of R f — a CF(U) y (T) z Formula 1C wherein R f is a linear or branched perfluoroalkyl radical Z(C m F 2m )—, m is 1, 3 to 20, or a mixture thereof; Z is F when m is 1 and Z is selected from F, Cl, or H when m is 3 to 20 or a mixture thereof; a is 13 or 14; y and z are each 1; U is F; and T is —X wherein X is I or Br, comprising a) contacting a perfluoroalkyl metallic compound of formula (R f ) (v−w) MX w wherein R f is a linear or branched perfluoroalkyl radical Z(C m F 2m )—, M is selected from the group consisting of Zn, Cd, Mg, Ca, and amalgams thereof with Hg, X is I or Br, v is the valence of M, and w is 1, with a CO 2 to generate the corresponding acid R f — a COOH; b) contacting the acid from step a) with a fluorinating agent to yield R f — a C(O)F; c) contacting the R f — a C(O)F with a substituted trifluorooxirane in the presence of a fluoride ion source to yield R f — a CF 2 —O—CF[(CF 2 ) p R″]—C(O)F wherein R″ is H or F and p is 1 to 8; and d) contacting R f — a CF 2 —O—CF[(CF 2 ) p R″]—C(O)F with a metal iodide or metal bromide and heating to yield R f — a CF(U) y (T) z .