THE INVESTIGATION OF SOLID-STATE CATALYTIC-HYDROGENATION OF ORGANIC-COMPOUNDS .2. THE SYNTHESIS OF TRITIUM LABELED VALINE

We report here the investigation of solid-state catalytic hydrogenation (SCH) of unsaturated compounds, used for the synthesis of tritium labelled valine. The effect of the solid-state components ratio, tritium pressure and reaction temperature on the reaction rate has been investigated. It has been found that the SCH reaction rate depends linearly on tritium pressure in the 5-50 kPa interval. H-3 NMR spectroscopy was used to determine the distribution of tritium label in synthesized valine. It was found, that the distribution of tritium label in the product molecules depends both on the precursor compound structure and the reaction temperature. SCH activation energy was determined to be equal to 11 kcal/mol. The application of solid-state isotope exchange for tritium labelling of unsaturated compounds has been shown for 3,3-dimethyl-2-benzoylaminoacrylic acid.