1-(2,3,5-Tri-O-acetyl-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxylic Acid Methyl Ester-13C2 is the labeled analogue of 1-(2,3,5-Tri-O-acetyl-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxylic Acid Methyl Ester (T767035), a reactant used in the synthesis of azole nucleoside 5'-MP mimics (P1Ms) as IMP dehydrogenase inhibitors.