4-(5-Methyl-1,3,4-thiadiazol-2-ylthio)piperidine trifluoroacetate (59 mg, 0.18 mmol) was dissolved in dry acetonitrile (1.5 mL). To the solution were added 1-acetyl-N-(3-chlorophenyl)-N-(3-chloropropyl)-4-piperidinecarboxamide (50 mg, 0.14 mmol), potassium carbonate (77 mg, 0.56 mmol) and potassium iodide (23 mg, 0.14 mmol), and the mixture was stirred at 80° C. for 5 hours. The mixture was cooled to room temperature, and to the mixture was added saturated sodium chloride solution (3 mL). The mixture was extracted three times with ethyl acetate (2 mL). The extracts were combined and concentrated under reduced pressure. The concentrate; was purified by using HPLC to give the titled compound as a colorless oily substance (32.2 mg, 28%).
