PURPOSE: To obtain the subject substances by chlorinating a mixture of 4-tert- butyltoluene with 3,5-di-tert-butyltoluene in the presence of a Lewis acid and simple substance of sulfur, providing a 2,5-dichlorinated substance of the former and 2,6-dichlorinated substance of the latter, separating both and then separately bringing each into contact with toluene.

CONSTITUTION: A mixture of 4-tert-(or isopropyl)toluene (BT) with 3,5-di- tert-butyl(or isopropyl)toluene (DBT) is chlorinated in the presence of a Lewis acid and simple substance of sulfur at 10-30°C to produce a 2,5-dichlorinated substance of the BT and a 2,6-dichlorinated substance of the DBT, which are subsequently separated and then separately brought into contact with ≥2 mol toluene to carry out transalkylation and simultaneously afford the subject substances. Specifically, the BT is partialy alkylated in the presence of the Lewis acid to provide a mixture of the BT with the DBT, which is subsequently used as a raw material for the aforementioned process. The BT produced by the transalkylation is circulated for use. The ratio of the produced two components can be optionally changed.