US Patent 7351870 Synthesis of carbon-labeled perfluoroalkyl compounds

Various 13C and 14C carbon labeled compoundsRf—bCF(U)y(T)zFormula 1A orRf—bCF2bCF(U)y(T)zFormula 1BwhereinRf is a linear or branched perfluoroalkyl radical Z(CmF2m)—,m is 1, 3 to 20, or a mixture thereof;Z is F when m is 1, and Z is F, Cl, or H when m is 3 to 20 or a mixture thereof;b is 13 or 14;y is 1, and z is 0 or 1; andwhen y and z are each 1, U is F, and T is selected from the group consisting of monovalent radicals —X wherein X is I or Br, —CH2—CH2—X, —CH═CH2, —CH2—CH2—OH, —CH2—COOH, —CH2OH, —bCH2OH, —COOH, —bCOOH, —O—CF(CF3)—C(O)F, —O—CF(CF3)—X, —SO2Y wherein Y is H, F or Cl, and —SO3H; andwhen y is 1, and z is 0, U is selected from the groupconsisting of divalent radicals ═CH—COOH, ═CH—CH2—OH, and ═O, are disclosed, and a process for their preparation which selectively introduces 13C and 14C carbon labels into a fluoroalkyl chain.