In a 1-l. round-bottomed flask, equipped with a reflux condenser carrying a calcium chloride tube, are placed 166 g. (103 cc., 1 mole) of technical tetrachloroethylene, 300 g. (200 cc., 2.5 moles) of dry chloroform, and 27 g. (0.2 mole) of anhydrous aluminum chloride. The mixture is refluxed gently on the steam bath for fifteen hours (Note 1), cooled to room temperature, and poured into a 1-l. separatory funnel half filled with crushed ice. The organic layer is washed several times with water and dried over calcium chloride or soluble anhydrite. By fractionation at atmospheric pressure through an efficient column, 160–165 g. of chloroform is recovered. Distillation of the unsym.-heptachloropropane fraction at diminished pressure gives material boiling at 110–113°/10 mm., or 137–140°/32 mm., and melting at 29–30°. The yield is 250–266 g. (88–93 per cent of the theoretical amount) (Note 2).