1-Chloro-2-(α-chlorophenylmethyl)benzene-d5 is the isotope labelled analog of 1-Chloro-2-(α-chlorophenylmethyl)benzene (C427570); a reagent in the synthesis of bifonazole analogs which have antibacterial and antifungal activities. It is also used in the preparation of diphenylpiperazine N-type calcium channel inhibitors.