Synthesis of carbon-labeled perfluoroalkyl compounds
View Patent ↗Various 13 C and 14 C carbon labeled compounds R f — b CF(U) y (T) z Formula 1A or R f — b CF 2 b CF(U) y (T) z Formula 1B 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 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; and when 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, —CH 2 —CH 2 —X, —CH═CH 2 , —CH 2 —CH 2 —OH, —CH 2 —COOH, —CH 2 OH, — b CH 2 OH, —COOH, — b COOH, —O—CF(CF 3 )—C(O)F, —O—CF(CF 3 )—X, —SO 2 Y wherein Y is H, F or Cl, and —SO 3 H; and when y is 1, and z is 0, U is selected from the group consisting of divalent radicals ═CH—COOH, ═CH—CH 2 —OH, and ═O, are disclosed, and a process for their preparation which selectively introduces 13 C and 14 C carbon labels into a fluoroalkyl chain.
1. 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 .
2. 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
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 (R f )—X wherein R f and X are as defined above with R—Mg—X wherein R is C 1 -C 4 alkyl to yield R f —Mg—X,
b) contacting R f —Mg—X with a CO 2 to yield R f — a COOH,
c) contacting the R f — a COOH from step b) with N,N-diethylaminosulfur trioxide to yield R f — a C(O)F;
d) contacting the R f — a C(O)F with hexafluoropropylene oxide in the presence of KF to yield R f — a CF 2 —O—CF(CF 3 )—C(O)F;
e) contacting R f — a CF 2 —O—CF(CF 3 )—C(O)F with a metal iodide or metal bromide to yield R f — a CF 2 —O—CF(CF 3 )—I or R f — a CF 2 —O—CF(CF 3 )Br;
f) heating R f — a CF 2 —O—CF(CF 3 )—I or R f — a CF 2 —O—CF(CF 3 )Br to yield R f — a CF 2 —I or R f — a CF 2 Br respectively.