Synthesis of selectively 3H or 14C-labeled 2-(4-(2-thienylcarbonyl)phenyl)propionic acid

2-(4-(2-Thienylcarbonyl)phenyl)propionic acid (suprofen), an anti-inflammatory agent, was labeled with tritium or carbon-14 for the purpose of investigating its metabolic fate in animals. The selectively tritiated suprofen (26.3-32.1 GBq (710-867 mCi)/mmol) was obtained by catalytic dehalogenation of the brominated precursor with 185-370 GBq (5-10 Ci) of tritium gas. The labeled position of the suprofen was confirmed by spectral data of the deuterated suprofen similarly synthesized. On the other hand, suprofen-14C (48.8 MBq (1.4 mCi)/mmol) was obtained by five-step synthesis from toluene [methyl-14C] in a 19% yield.