(2S)-1-(4-Chlorophenyl)-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)-3-pentanone-d4 is an intermediate in synthesizing Paclobutrazol-(phenyl-d4). It is a labeled version of Paclobutrazol (P133000), which is a triazole fungicide used as an plant growth retardant in inhibiting gibberellin biosynthesis.