Exploring the active site of phenylethanolamine N-methyltransferase with 3-hydroxyethyl- and 3-hydroxypropyl-7-substituted-1,2,3,4-tetrahydroisoquinolines

3-Hydroxyethyl- and 3-hydroxypropyl-7-substituted-tetrahydroisoquinolines (9, 10, 16, and 17) were synthesized and evaluated for their phenylethanolamine N-methyltransferase (PNMT) inhibitory potency and affinity for the alpha(2)-adrenoceptor. Although alpha(2)-adrenoceptor affinity decreased for these compounds, selectivity was not gained over the parent 3-hydroxymethyl compounds (1, 2) due to a loss in PNMT inhibitory potency.