To a solution of 3-(4-bromo-phenyl)-1-methyl-piperazine (1.0 g, 3.92 mmol), pyrazolo[1,5-a]pyridin-3-yl-acetaldehyde (753 mg, 4.70 mmol) and acetic acid (1.2 mg) in tetrahydrofuran (15 mL) was added sodium triacetoxyborohydride (1.92 g, 8.62 mmol) and the resulting mixture was stirred at room temperature for 4 h. The reaction mixture was diluted with ethyl acetate, washed with a saturated aqueous sodium bicarbonate solution, a saturated aqueous solution of sodium chloride, dried over magnesium sulfate, filtered and concentrated in vacuo. Purification via flash silica gel column chromatography (heptane/ethyl acetate) gave 3-{2-[2-(4-bromo-phenyl)-4-methyl-piperazin-1-yl]-ethyl}-pyrazolo[1,5-a]pyridine (786 mg, 50% yield). LCMS (m/z): 401.00 (M+1).
