A suspension of 0.17 g (0.39 mmol) of 1-{2-[4-(6-trifluoromethyl-benzo[b]thiophen-3-yl)-piperazin-1-yl]-ethyl}-cyclopropanecarboxylic acid in 10 mL dichloromethane under nitrogen was treated with 1 mL of oxalyl chloride followed by 3 drops of DMF. After 2 hours the reaction was concentrated to a slurry, diluted with 10 mL DMF and treated with 0.10 g (0.78 mmol) of 1-(3-aminopropyl)imidazole followed by 0.12 g (1.2 mmol) of triethylamine. After 12 hours the reaction was poured into aqueous saturated sodium bicarbonate and extracted with ethyl acetate. The organic layer was separated, dried and concentrated to deliver an oil. Chromatographic purification gave 0.075 g (38%) of the desired final product as an oil.
