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Sodium perfluoroalkanesulfinate, R_FSO_2Na [R_F=Cl(CF_2)_4, 1a; CF_3(CF_2)_5, 1b; Cl(CF_2)_6,1c] reacted with bromine in aqueous solution to give the corresponding sulfonyl bromide R_FSO_2Br(2a--2c) and in acetonitrile or acetic acid, to form perfluoroalkyl bromide R_FBr (3a--3c). Heatingin acetonitrile at 80℃, 2a--2c were converted smoothly into 3a-3c. However, reaction of sodiumα,α--dichloropolyfluoroalkanesulfinate RCCl_2SO_2Na (R= CF_3, Cl(CF_2)_n, n = 2, 4, 6, 5a-5d) withbromine in aqueous solution gave directly the corresponding bromoalkanes 1--bromo--1,1-di-chloropolyfluoroalkane RCCl_2Br (6a-6d). In aqueous potassium iodide solution, 1a--1c, 5a and5b also reacted with iodine to form the corresponding iodo-polyfluoroalkane 4a-4c, 7a and 7b di-rectly. 6a and 7a underwent free radical addition to alkene readily in the presence of free radicalinitiator and reacted with Na_2S_2O_4 in the usual way to form α,α--dichloropolyfluoroethane sulfinate(5a). 5a was stable in strong acid, but reacted with strong base to yield 10. 5a was oxidised byhydrogen peroxide to the sulfonate 11 and reduced by zinc in dilute acid to from the α--chlorosulfinate 12.
(2a - 2c) with perfluoroalkanesulfinate and R_FSO_2Na [R_F = Cl (CF_2) _4, 1a; CF_3 (CF_2) _5, 1b; The reaction of sodium α, α - dichloropolyfluoroalkanesulfinate RCCl_2SO_2Na (R = CF_3, Cl (CF_2) _n, n = 2, 4, 6, 5a-5d) with bromine in aqueous solution gave gave the corresponding bromoalkanes 1 - bromo - 1,1- di-chloropolyfluoroalkane RCCl_2Br (6a-6d). In aqueous potassium iodide solution, 1a - 1c, 5a and 5b also reacted with iodine to form the corresponding iodo-polyfluoroalkane 4a-4c, 7a and 7b di-rectly. 6a and 7a underwent free radical addition to alkene readily in the presence of free radicalinitiator and reacted with Na_2S_2O_4 in the usual way to form α, α - dichloropolyfluoroethane sulfinate (5a). 5a was stable in strong aci d, but reacted with strong base to yield 10. 5a was oxidized byhydrogen peroxide to the sulfonate 11 and reduced by zinc in dilute acid to the α-chlorosulfinate.