Sodium metal (0.116 g, 4.98 mmol) was added to ice cold ethanol (10 mL). When all the sodium metal dissolved, hydroxylamine hydrochloride (0.346 g, 4.98 mmol) was introduced in one portion. The suspension was stirred at room temperature for 15 minutes and a solution of 6-[4-(2-trifluoromethylbenzoyl)piperazin-1-yl]-pyridazine-3-carbonitrile (0.900 g, 2.49 mmol) in ethanol (2 mL) was then added. The mixture was further stirred at room temperature overnight. The solvent was removed in vacuo and the residue was suspended in ethyl acetate (10 mL) and filtered through celite. The filtrate was concentrated and the product was purified by column chromatography. The title compound was obtained as a pale yellow syrup in 55% yield (0.54 g). 1H NMR (300 MHz, CDCl3) δ 7.82 (d, J=9.6 Hz, 1H), 7.45 (d, J=7.6 Hz, 1H), 7.70-7.52 (m, 2H), 7.35 (d, J=7.4 Hz, 1H), 6.95 (d, J=9.5 Hz, 1H), 5.53 (s, 2H), 4.10-3.95 (m, 1H), 3.98-3.82 (m, 1H), 3.82-3.60 (m, 4H), 3.32 (t, J=5.1 Hz, 2H). 13C NMR (75 MHz, CDCl3) δ 157.5, 147.5, 142.1, 132.2, 130.2, 127.3, 125.1, 123.2, 110.8, 44.2, 42.6, 42.3, 39.1 MS (ES+) m/z 395.3 (M+H).
