To a mixture of 1.00 g (3.96 mmol) of 4-(diphenylmethyl)-piperazine and 1.28 g (5.57 mmol) of 2-(2-chloroethylthio)benzothiazole, were added 10 ml of dioxane, 2 ml of dimethylformamide and 0.85 g (6.15 mmol) of potassium carbonate, and the mixture was stirred under reflux for 3 hours. After the reaction, the insolubles were filtered off, and the filtrate was concentrated. The residue was separated by silica gel column chromatography using a mixture of chloroform and methanol in the volume ratio 30:1 as the developing solvent, and the desired fraction was concentrated under reduced pressure to give 0.61 g (35%) of 2-[2-[4-(diphenylmethyl)-1-piperadinyl]-ethylthio]benzothiazole as an oil.
