Empagliflozin, 
(2S,3R,4R,5S,6R)-2-[4-chloro-3-[[4-[(3S)-oxolan-3-yl]oxyphenyl]methyl]phenyl]-6-(hydroxymethyl)oxane-3,4,5-triol 
was recently approved by the FDA for the treatment of chronic type 2 diabetes 
mellitus. Herein, we report the synthesis of carbon-13 and carbon-14 labeled 
empagliflozin. Carbon-13 labeled empagliflozin was prepared in five steps and in 
34% overall chemical yield starting from the commercially available 
α-D-glucose-[(13)C6]. For the radiosynthesis, the carbon-14 atom was introduced 
in three different positions of the molecule. In the first synthesis, Carbon-14 
D-(+)-gluconic acid δ-lactone was used to prepare specifically labeled 
empagliflozin in carbon-1 of the sugar moiety in four steps and in 19% overall 
radiochemical yield. Carbon-14 labeled empagliflozin with the radioactive atom 
in the benzylic position was obtained in eight steps and in 7% overall 
radiochemical yield. In the last synthesis carbon-14 uniformly labeled phenol 
was used to give [(14)C]empagliflozin in eight steps and in 18% overall 
radiochemical yield. In all these radiosyntheses, the specific activities of the 
final compounds were higher than 53 mCi/mmol, and the radiochemical purities 
were above 98.5%.