VERFAHREN ZUR HERSTELLUNG VON CHLOR, BROM ODER IOD SOWIE ETHERSAUERSTOFF ENTHALTENDEN, WEITGEHEND PERFLUORIERTEN ALKYLVERBINDUNGEN.

摘要

In prodn. of perfluoro 1,2-propyleneglycol ether derivs. of formula (I) by reaction of a salt of a tetrafluoropropionic acid deriv. of formula (II) with a halogen at room temp. or elevated temp. in the absence of water: (A = H, F, Cl, Br, I or -O-(-CF(CF3)-CF2-O-)q-CF(X)-CF3; A (asterisk) = H, F, Cl, Br, I or -O-(-CF(CF3)-CF2-O-)q-CF(CF3)-COOH; Rf = 2-10C perfluoroalkenyl; or Rf+A or Rf+a(asterisk) = perfluoro-3,6 dimethyl-1,4-dioxan-2-yl; p, q = 0-10; X = Cl, Br or I) the salt of (II) is an alkali; alkaline earth or quat. ammonium salt and the halogen is chloride, bromine or iodine or a cpd. which releases chlorine, bromine or iodine under the reaction conditions. Cpd. of formula (I) in which (1) A is F, Rf is -CF2CF2CF2- and p is 0-6 (pref. 0-2) or (2) A+Rf is perfluoro-3,6-dimethyl-1,4-dioxan-2-yl and p is 0-4 are new and also claimed. intermediates, e.g. for addition reactions with olefins to give products suitable for use as comonomers. The iodo cpds. are also useful as lasee media. Nontoxic cpds., e.g. the bromo cpd. C3F7-O-CF(CF3)-CF2-O-CF(CF3)-Br, are of interest for blood substitute emulsions. Chloro cpds. can be used as special inert fluids, e.g. in the medical sector. The new process gives good yields without the use of expensive silver salts.