Synthesis of [ 2 H 7 ]indatraline

Deuterium‐labelled indatraline was synthesized in high efficiency employing a Friedel–Crafts alkylation of [ 2 H 6 ]benzene with ( E )‐3‐(3,4‐dichlorophenyl)acrylic acid as a key step. The desired labelling of the final compound was ascertained in two ways, by incorporation of [ 2 H 6 ]benzene in the target molecule and additionally by deuterium transfer to the non‐deuterated aryl moiety of the Friedel–Crafts alkylation product from [ 2 H 6 ]benzene, the latter thus serving as reagent and solvent.