To a solution of (3′-piperazin-1-yl-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-4-yl)-methanol (0.145 g, 0.524 mmol, 1 eq) and 1-ethyl-1H-pyrazole-4-carbaldehyde (97.69 mg, 0.787 mmol, 1.5 eq) in 1,2-dichloroethane (10 mL) add sodium triacetoxyborohydride (166.79 mg, 0.787 mmol, 1.5 eq) in one portion as a solid. Stir the mixture at room temperature under nitrogen for 20 hr. Add 2 M aqueous sodium hydroxide solution (20 ml) and DCM (20 ml). Separate using a phase separator and extract the aqueous layer with DCM (10 ml). Concentrate the combined organic extracts and purify by high pH reverse phase HPLC. Dissolve this material (120 mg, 0.31 mmol) in the minimum quantity of 50% aqueous acetonitrile. Add 2 M aqueous hydrogen chloride (155 μL, 0.31 mmol) and lyophilize to give the title compound (127 mg, 58%). MS (m/z): 385.2 (M+1).
