1,2,3,4-Tetrahydro-1-(3-pyridinylmethyl)-2-naphthalenamine bis-hydrochloride 4 (0.75 g, 2.41 mmol) was reacted with 2-(4-acetyl-4-phenyl-piperidin-1-yl)acetic acid (0.86 g, 2.65 mmol), N,N-diisopropylethylamine (2.0 mL, 11.3 mmol) and HBTU (1.01 g, 2.65 mmol) in N,N-dimethylformamide (15 mL) at room temperature for 2 h as described above in EXAMPLES 7–8. The product was collected by filtration from the aqueous work-up. This material was dissolved in isopropanol (˜30 mL) and treated with a saturated solution of hydrochloric acid in isopropanol (˜5 mL). The solvent was evaporated in vacuo, and the residue was triturated with diethyl ether to give 4-acetyl-4-phenyl-N-[cis-1,2,3,4-tetrahydro-1-(3-pyridinylmethyl)-2-naphthalenyl]-1-piperidineacetamide bis-hydrochloride 21 as an amorphous pale yellow solid (1.2 g, 90%): MS m/e 482 (MH+) (FIG. 7).
