3-[(Diethylamino)carbonyl]benzoic-d10 Acid Methyl Ester is an intermediate in synthesizing ω-Hydroxy-DEET-D10 (H934202), a labelled analogue of ω-hydroxy-DEET (H934200). The compound is also a labelled analogue of 3-[(Diethylamino)carbonyl]benzoic Acid Methyl Ester (D443730), which is used in the synthetic preparation of internal standards in the determination of carboxylic acid metabolites of N,N-diethyl-m-toluamide compounds in rat urine.