Solid-Phase Catalytic Hydrogenation of Orotic Acid and 5-Bromouracil with Tritium on a Copper Catalyst

Abstract

The performance of a copper-based catalyst in solid-phase catalytic hydrogenation of orotic acid and 5-bromouracil with gaseous tritium was studied. Hydrogen isotope exchange in the carboxy group of orotic acid was combined with decarboxylation in a one-pot process. The catalyst performance was judged from the molar radioactivity of [6-3H]uracil and [5-3H]uracil formed by catalytic hydrogenation with gaseous tritium of orotic acid and 5-bromouracil, respectively. In solid-phase catalytic dehalogenation, the performance of the copper-based catalyst is comparable with that of the palladium catalyst, but this level is attained at a higher temperature. To evaluate the performance of the copper catalyst in isotope exchange reactions, additional studies with a wider range of substrates are required.