In order to investigate the metabolism of the herbicide MCPA-isopropyl [isopropyl 2-(4-chloro-2-methylphenoxy)acetate] in the environment, two isotopologues of this regiospecifically deuterium-labeled in selected positions compound were synthesized. The synthesized compounds were labeled at the methylene group, isopropyl 2-(4-chloro-2-methylphenoxy) [2,2-2 H 2 ]acetate, and at the isopropyl group, [ 2 H 7 ]isopropyl 2-(4-chloro-2-methylphenoxy)acetate.