Synthesis of 14C norfenfluramine

Article abstract of DOI:10.1002/jlcr.2580140410

The starting materials ¹⁴C-Trifluoromethylbenzoic acid and ¹⁴C bistrifluoromethyl-3 -benzophenone were prepared by carbonation of appropriate Grignard reagents. The labelled benzophenone was oxidized in high yield to give ¹⁴C-trifluoromethylbenzoic acid. This ¹⁴C carboxylic compound was transformed into aldehyde which was condensed with nitroethane to form ¹⁴C-trifluoromethyl-3-phenyl-1-nitro-2-propene, 1-9. The latter compound was reduced with lithium aluminium hydride to give ¹⁴C-norfenfluramine. The overall yield was 45,5% at a specific activity of 1,65 mCi/mM.