Abstract Naproxen, a well-known non-steroidal anti-inflammatory drug, and its 6-O- desmethylated metabolite have been labelled with 2 H.(R, S)-Naproxen 7 labelled with 2 H was obtained in five steps using the commercially available [2 H 3] iodomethane 5 as the stable labelled reagent. The demethylation of 7 using 48% HBr in 1-butyl-3- methylimidazolium tetrafluoborate gave the corresponding 2 H-labelled 6-O- ...
