To a solution of 4-[3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine (1.9 mmol) in 10 mL N,N-dimethylformamide were added 2-iodopropane (2.9 mmol) and cesium carbonate (2.1 mmol). The reaction mixture was stirred overnight at room temperature and the solvent was then evaporated. The residue was diluted with water and extracted three times with ethyl acetate. The combined organic extracts were dried over MgSO4 filtered and concentrated. The residue was purified by chromatography on silica gel (dichloromethane:ethyl acetate 20:1 to 5:1) to afford 0.37 g of 4-[1-isopropyl-3-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine (61% yield) and 63 mg of 4-[1-isopropyl-5-(5-chloro-2-thienyl)-1H-pyrazol-4-yl]pyridine (10% yield).
