The synthesis of five classes [type A, cycloalkylethanolamines; type B, n-alkylethanolamines; type C, 2-(aminomethyl)-2-n-alkanols; type D, 1-(aminomethyl)cycloalkanols; type E, sec-alkylethanolamines] of nonaromatic analogues of β-phenylethanolamine and an evaluation of their inhibitory potency (IC₅₀) for phenylethanolamine N-methyltransferase (PNMT) are described. The key intermediates for the synthesis of the ethanolamines were the appropriate aldehydes or ketones. Type A aldehydes 11a (cyclobutyl) and 13a (cycloheptyl) were prepared from corresponding acids via reduction to alcohols with lithium aluminum hydride (LiAlH₄) and oxidation to aldehydes with pyridinium chlorochromate (PCC). Aldehydes 15a (cycloundecyl) and 41a (adamantyl) of type A were obtained by oxidizing corresponding alcohols with PCC. Cyclononanecarboxaldehyde (type A, 14a) was synthesized via a multistep route starting with Favorskii rearrangement of 2-bromocyclodecanone to cyclononanecarboxylic acid, followed by LiAlH₄ reduction to the alcohol and PCC oxidation to the aldehyde. Aldehydes or ketones were converted to cyanohydrin ethers with trimethylsilyl cyanide, then reduced to target ethanolamines using LiAlH₄. The ethanolamines were tested as PNMT inhibitors via the LCEC assay. The most potent inhibitors were type A compounds 8 (cyclooctyl), 13c (cycloheptyl), 14c (cyclononyl), 15c (cycloundecyl) and type D compounds 26c (cyclononyl), 27c (cycloundecyl) with IC₅₀ values ranging from 6 to 17 μM. It is concluded that the PNMT binding site accepts hydrophobic groups with optimal length (~6.4 Å) and width (~2.5 Å), has significant height restriction, and the ethanolamine side chain prefers to lie away from and along the longitudinal axis of the hydrophobic group. Ethanolamines with an ethanolamine side chain attached to a cycloalkyl ring (types A and D) are considerably more potent inhibitors of PNMT than open-chain compounds (types B, C, E) with the same total number of carbon atoms.