1-Methyl-2-chloromethyl-5-benzyloxypyridin-4(1H)-one Hydrochloride-d5 is the isotope labelled analog of 1-Methyl-2-chloromethyl-5-benzyloxypyridin-4(1H)-one Hydrochloride (M295140); a reagent in the synthesis of vanadyl-thiazolidinedione combination agents used for diabetes therapy.