Sodium azide (137 mg, 2.1 mmol) was added at 0° C. to a solution of 1-(3-chlorobenzyl)-7-(3,4-dihydro-1H-isoquinolin-2-yl)-2,3-dimethyl-1H-pyrrolo[2,3-c]pyridin-5-carbonitrile (300 mg, 0.7 mmol) prepared in Example 689 and ammonium chloride (74.9 mg, 1.4 mmol) in anhydrous N,N-dimethylformamide (10 ml). The reaction mixture was refluxed overnight. 6% sodium nitrite solution was added to the reaction mixture, which was then extracted with ethyl acetate. The organic layer was dried on anhydrous magnesium sulfate and then concentrated under reduced pressure. The resulting residue was purified with silica gel column chromatography (ethyl acetate/n-hexane=1/3, v/v) to give 110 mg of the titled compound as a white solid. (Yield: 33%).
