Abstract: A process for the preparation of 2,4,5-trichlorophenol and 2,4,5-trichlorophenoxyacetic acid free of 2,3,7,8-tetrachloro-dibenzo-p-dioxin contamination by the steps of nitrating 1,2,4-trichlorobenzene, reducing the resulting 1,2,4-trichloro-5-nitrobenzene, diazotizing the resulting 2,4,5-trichloroaniline, hydrolyzing the resulting 2,4,5-trichlorobenzenediazonium salt and recovering 2,4,5-trichlorophenol. The 2,4,5-trichlorophenol is reacted with monochloroacetic acid to give 2,4,5-trichlorophenoxyacetic acid. Both the 2,4,5-trichlorophenol and the 2,4,5-trichlorophenoxyacetic acid produced by the process are analytically free of 2,3,7,8-tetrachloro-dibenzo-p-dioxin in analytical tests sensitive to 1 part per billion.

Abstract: The process for the chlorination of aromatic compounds of the formula: ##STR1## wherein R is a member selected from the group consisting of hydrogen, carboxymethyl, and carboxyethyl and R.sub.x is a member selected from the group consisting of hydrogen, 2-methyl, 2,5-dichloro, and 2-chloro, with the proviso that when R is hydrogen, R.sub.x is 2,5-dichloro, consisting of reacting said aromatic compound with sulfuryl chloride in the presence of elemental sulfur or certain sulfur compounds as a catalyst, optionally together with the presence of a Friedel-Crafts acid catalyst and/or an inert organic solvent at temperatures of from 30.degree. C. to 150.degree. C., and recovering a para chlorinated compound.

Abstract: A method for the reduction of the content of toxic chlorinated aromatic compounds such as chlorinated aromatic dioxins and especially chlorinated dibenzo-p-dioxins in reaction products to virtually zero consisting essentially of reacting a mass containing chlorinated aromatic dioxins with an amount, in excess of stoichiometrical based on the total organic halogen content, of alkaline reactants selected from the group consisting of (1) alkali metal alcoholates of alcohols selected from the group consisting of alkanols having from 1 to 5 carbon atoms, polyalkoxyalkane glycols having 4 to 20 carbon atoms, alkanepolyols having from 2 to 5 carbon atoms and 2 to 3 hydroxyls, and monoalkyl ethers of such alkanepolyols with alkanols having from 1 to 4 carbon atoms, or (2) mixtures of said alcohols with alkaline reactants selected from the group consisting of alkali metal hydroxides and carbonates, at a reaction temperature of from 140.degree. C. to 220.degree. C.