4-(6-Methoxy-4-phenylpyridazin-3-yl)benzaldehyde (2-2; 80 mg, 0.27 mmol) was dissolved in dry dimethylformamide (2 mL) and 2-(3-piperidin-4-yl-1H-pyazol-5-yl)pyridine (1-4; 99 mg, 0.43 mmol) and acetic acid (0.14 mL, 2.3 mmol) were added. After stirring for 15 min., sodium triacetoxyborohydride (116 mg, 0.54 mmol) was added and the reaction mixture was stirred at ambient temperature for 12 hours. This reaction mixture was partially evaporated and the residue chromatographed on a silica gel column eluting with a 0-5% methanol/ethyl acetate sat'd with NH4OH. 3-methoxy-5-phenyl-6-(4-{[4-(5-pyridin-2-yl-1H-pyrazol-3-yl)piperidin-1-yl]methyl}phenyl)pyridazine (2-3) was obtained as a nearly pure viscous oil. NMR (CDCl3): δ8.60 (1H, d, J=5 Hz), 7.69-7.72 (2H, m), 7.23-7.35 (6H, m), 7.17 (2H, br d, J=7 Hz), 6.98 (1H, s), 6.61 (1H, s), 4.22 (3H, s), 3.52 (2H, s), 2.95 (2H, d, J=12 Hz), 2.72 (1H, m), 2.10 (2H, br t, J=1 Hz), 1.97 (2H, br d, J=12 Hz), 1.81 (2H, br q, J=11).
