L. P. Kingston

Iridium-catalysed labelling of anilines, benzylamines and nitrogen heterocycles using deuterium gas and cycloocta-1,5-dienyliridium(I) 1,1,1,5,5,5-hexafluoropentane-2,4-dionate

A wide range of variously substituted anilines, benzylamines, and nitrogen heterocycles may be conveniently deuterated by exchange with deuterium gas and cycloocta-1,5-dienyliridium(I) 1,1,1,5,5,5-hexafluoropentane-2,4-dionate. The isotopic exchange can be carried out efficiently in dimethylformamide or dimethylacetamide, hence it is directly applicable to the deuteration of polar compounds such as pharmaceuticals. Isotope incorporation is rapid and yields ortho-regiospecificity.

Parallel chemistry investigations of ortho-directed hydrogen isotope exchange between substituted aromatics and isotopic water: novel catalysis by cyclooctadienyliridium(I)pentan-1,3-dionates

Abstract Novel iridium-based catalysts which promote ortho -directed hydrogen isotope exchange between substituted aromatics and isotopic water have been identified via a combination of screening and subsequent ligand optimisation. The catalysts are more active, operate at lower temperature and are applicable to a wider variety of substrates than previously known systems.

Preparation of remacemide hydrochloride labelled with carbon‐14, carbon‐13, deuterium and tritium

The anti-epileptic agent remacemide hydrochloride has been prepared labelled with 14C, from [carbonyl-14C]acetophenone, and with 13C from [13C6]benzene, [1,2-13C]acetyl chloride and [1-13C]glycine. [2-3H]Glycine was utilised to prepare remacemide labelled with tritium at low specific activity. In addition other 2H- and high specific activity 3H-isotopomers of the drug, and of an active metabolite of the drug, were prepared by hydrogen isotope exchange methodology. The R-12C/S-14C and S-12C/R-14C pseudoracemic drugs were also prepared by a synthesis involving resolution of a 14C-labelled amine intermediate via fractional crystallisation of the dibenzoyltartrate salts. Copyright