A process is developed for the synthesis of 1,1,1-trichloroethane from 1,1,2-trichloroethane, a byproduct produced in the vinyl chloride process. Catalytic dehydrochlorination of the 1,1,2-trichloroethane produces vinylidene chloride, 1,2-dichloroethylene and hydrogen chloride, of these vinylidene chloride and hydrogen chloride react subsequently to form the 1,1,1-trichloroethane in a Friedel-Craft catalytic process. Barium chloride or copper chloride of 5 to 30 percent by weight supported on the activated carbon is used as catalyst. The selectivity for vinylidene chloride is attained up to 35 percent in the reaction temperature range of 400 ℃ to 500 ℃ using 20 to 30 percent barium chloride catalyst. It is also confirmed that the synthesis of 1,1,1-trichloroethane is a first order reaction with respect to the concentration of vinylidene chloride when excess hydrogen chloride gas is bubbled continuously into the catalytic slurry reactor, and its rate is linearly proportional to the concentration of anhydrous aluminum chloride catalyst.