The synthesis and characterization of some l-(phenylalkyl) imidazole-2-thiones as a novel class of “multisubstrate” inhibitors of dopamine@-hydroxylase (DBH) are described. These inhibitors incorporate structural features that resemble both tyramine and oxygen substrates, and as evidenced by steady-state kinetics, they appear to bind both the phenethylamine binding site and the active site copper atom (s) in DBH. A series of structural congeners ...