To a solution of 1-[3-(3-bromo-9H-xanthen-9-yl)-8-aza-bicyclo[3.2.1]oct-8-yl]-2,2,2-trifluoro-ethanone, 2j (1.8 g, 3.86 mmol) in DMF (40 mL) was added copper cyanide (0.69 g, 7.72 mmol) and potassium iodide (50 mg), and the mixture was heated to reflux for 18 h. More copper cyanide (0.43 g) was added, and the mixture was heated to reflux for 30 h. The mixture was filtered and poured in ice-water. The solid was separated via filtration, washed with water, and air-dried. The crude product was purified via flash column chromatography (eluent gradient: 5% to 30% ethyl acetate in heptane) to yield 0.956 g (60%) of title compound 9-[8-(2,2,2-trifluoroacetyl)-8-aza-bicyclo[3.2.1]oct-3-yl]-9H-xanthene-3-carbonitrile, 3j. MS m/z (MH+) 412.8.
