use of ferric chloride the iron powder useful in this invention is preferably a fine powder of pure metallic iron preferably with a particle size smaller than 325 mesh iron powder may be added to the reactor by any means but powder slurry in carbon tetrachloride in tbp or in the mixture of both is preferred while iron powder is preferred any iron object can be used such as iron balls iron wire iron shavings and the like the co catalyst tbp is a chelating agent and also serves as solvent to help dissolve the solid catalyst the mole ratio of iron powder to tributylphosphate may be about 0 05 1 to about 500 0 1 preferably about 1 0 1 to about 100 0 1 and more preferably about 1 5 1 to about 10 1 the preferred concentration of the catalyst in the reaction mixture is from about 0 001 to about 20 weight percent preferably from about 0 01 to about 10 weight percent and more preferably from about 0 1 to about 5 weight percent generally the mole ratio of ccl 4 to vcm is from about 0 02 1 to about 50 1 preferably the ratio is from about 0 1 1 to about 4 0 1 and more preferably from about 1 1 to about 3 1 additional organophosphate co catalysts useful herein are the following triphenylphosphate tributylphosphate trimethylphosphate triethylphosphate tripropylphosphate or any similar organophosphate compound and mixtures of two or more.