Process for the preparation of fluorohalogenated ethers starting from fluorooxy-compounds and halogenated olefins

A process for the preparation of fluorohalogenated ethers having the formula:

• (R).sub.n C(F).sub.m --O--CAF--CA.sup.1 F.sub.2
• wherein A and A', alike or different from each other, are chlorine or bromine, R is an alkyl or polyether radical containing from 1 to 20 carbon atoms, wholly halogenated with bromine, chlorine and/or fluorine, n is an integer from 1 to 2, m is an integer equal to 3-n, said process consisting in reacting in liquid phase a fluoroxycompound (R).sub.n C(F).sub.m --OF with an olefin CAF.dbd.CA'F, at temperature between -150.degree. and 0.degree. C., characterized in that the fluoroxycompound is continuously fed into the reaction phase in the form of a solution having a concentration less than 50% by weight in an inert solvent, the olefin being fed in the liquid state, optionally in an inert solvent, all at the beginning into the reactor or continuously, in such a manner to have always an excess of the olefin in the reaction phase.