Fast and efficient synthesis of 14C labelled benzonitriles and their corresponding acids

Schou S C

J Label Compd Radiopharm 2009; 52(5): 173-176

http://dx.doi.org/10.1002/jlcr.1585

14C-Anthranilic acid has been prepared in a fast and efficient way in a two-step reaction in 82% overall radiochemical yield. Thus, 2-iodoaniline was transformed into 2-amino-[7-14C]-benzonitrile using a palladium catalyzed cyanation with zinc 14C-cyanide. Subsequent basic hydrolysis of the cyano group afforded [7-14C]-anthranilic acid. The method was successfully applied to a benzophenone scaffold, 4-iodophenol and 4-iodobenzoic acid producing the corresponding carboxylic acids in good to excellent radiochemical yields (62-82%) and with high specific activity (1.94-1.98 GBq/mmol).