The use of a mixture of lead dioxide and sulfur tetrafluoride as a reagent for the selective addition of fluorine to the double bond of halogenated olefins has been studied. This reagent generally affords higher yields under somewhat milder conditions than have been reported previously. Iodine-containing olefins have been fluorinated for the first time. Four new halocarbons, namely l, l-dichloro-1, 2-difluoroethane, dl-l, 2-dichloro-l, 2- ...
