Synthesis of isotopomers of dopamine labeled with deuterium or tritium

The synthesis of four isotopomers of dopamine labeled with deuterium or tritium is reported. The ring labeled [2′,5′,6′‐ 2 H 3 ]‐, and [2′,5′,6′‐ 3 H 3 ]‐dopamine were obtained using acid catalyzed isotopic exchange between dopamine and heavy or tritiated water respectively. Two selectively labeled isotopomers, i.e. [1R‐ 2 H]‐, and [1R‐ 3 H]‐dopamine were synthesized by enzymatic decarboxylation of L ‐DOPA using the enzyme tyrosine decarboxylase (EC 4.1.1.25) from Streptococcus faecalis . Copyright © 2006 John Wiley & Sons, Ltd.