2-Iodo-p-xylene (CAS NO.: ), with other names as , 2-iodo-1,4-dimethyl, could be produced through the following synthetic routes.

A 500-ml., round-bottomed flask equipped with a magnetic stirring bar and a glass stopper is charged with 110 ml. of trifluoroacetic acid and 54.34 g. (0.1008 mole) of solid (III) trifluoroacetate. A clear solution is obtained after 30 minutes of vigorous stirring. Upon addition of 10.6 g. (0.100 mole) of p-xylene, the reaction mixture turns brown. After vigorous stirring for 20 minutes, the trifluoroacetic acid is removed on a rotary evaporator with a bath temperature of 35°, and the residue is dissolved in 100 ml. of diethyl ether. The solvent is again evaporated, and the solid residue is dissolved in 100 ml. of ether. With ice cooling, a solution of 33.2 g. (0.200 mole) of potassium iodide in 100 ml. of water is added in one portion. After the resulting dark suspension is stirred vigorously for 10 minutes, a solution of 3 g. of sodium bisulfite in 30 ml. of water is added. Yellow thallium(I) iodide is removed by filtration after another 10 minutes of vigorous stirring and washed thoroughly with 150 ml. of ether. The aqueous layer is separated and extracted with two 60-ml. portions of ether. The combined ether extracts are washed once with 10% aqueous sodium hydroxide and twice with 20 ml. of water. After being dried over anhydrous magnesium sulfate for 1 hour, the ether is removed on a rotary evaporator. Distillation under reduced pressure yields 18.5–19.6 g. (80–84%) of pure 2-iodo-p-xylene, b.p. 110–113° (19 mm.).

Notice: Thallium salts are very toxic. This preparation should be carried out in a well-ventilated hood. The operator should wear rubber gloves.