The synthesis and resolution of tritiated 4-amino-3-phenylbutanoic acid ([3H]R- and [3H]S-β-phenylgaba)

A synthesis of [3H]R- and [3H]S-4-amino-3-phenylbutanoic acid ([3H]R- and [3H]S-β-phenylGABA) from the unsaturated intermediate by catalytic hydrogenation using tritium gas in the presence of palladium on charcoal is reported. The [3H]R- and [3H]S-diastereoisomers of pantolactone ester of β-phenylGABA were separated by HPLC.