(2-Chlorophenyl)diphenyl-d5-methanol (phenyl-d5) is a deuterated analog of (2-chlorophenyl)diphenylmethanol, where the phenyl rings are selectively labeled with deuterium (d5). This isotopic labeling enhances its utility in mass spectrometry and NMR studies, providing improved signal resolution and reduced background interference. The compound is particularly valuable in metabolic tracing, kinetic isotope effect (KIE) studies, and pharmaceutical research, where precise tracking of molecular interactions is required. Its stable deuterium incorporation ensures minimal isotopic exchange, maintaining structural integrity under experimental conditions. The presence of the 2-chlorophenyl group further enables selective functionalization, making it a versatile intermediate in synthetic chemistry and drug development.