1-(4-Amino-3,5-dichlorophenyl)-2-[[1-(methyl-d3)ethyl-1,2,2,2-d4]amino]ethanone is used in the invention related to a stable isotope-labeled clenproperol compound; Also, it is an intermediate used in the Clenproperol-d7 (C573002), which is a labeled related drug of Clenbuterol (C569998), a β-agonist which can be used as a growth promoter in farm animals.