Synthesis of carbon-14 labelled xenalipin - a potential hypolipidemic agent

Xenalipin 1 (4′‐trifluoromethyl‐2‐biphenylcarboxylic acid) was synthesized in the [14C]‐labelled form with specific activity 21.0 mCi/mmol suitable for metabolism and distribution studies in animals. The synthetic sequence involved conversion of [14C]‐ benzoic acid to the 4,4‐dimethyl‐2‐oxazoline derivative, formation of an organozinc compound, palladium‐catalyzed coupling of the arylzinc‐oxazoline with 4‐trifluoromethyliodobenzene, and acid hydrolysis. The radiochemical purity was 99.4%.