To a flame-dried reaction flask were added at room temperature and under an argon atmosphere commercially available 1-(4-fluorophenyl)-1H-imidazole (69.6 mg, 429 μmol), palladium(II)acetate (9.64 mg, 42.9 μmol), cesium fluoride (130 mg, 859 μmol), triphenylarsine (26.3 mg, 85.9 μmol) and 6-bromo-3-(4-fluoro-phenyl)-imidazo[1,2-a]pyridine (intermediate E) (125 mg, 429 μmol). Afterwards DMF (2.15 ml) was added successively by syringe at room temperature and under a stream of argon. The resulting mixture was allowed to stir at 140° C. under an argon atmosphere for 24 h. The reaction mixture was cooled to room temperature, water (10 ml) was added and the mixture was extracted with dichloromethane (2×40 ml). The combined organic layers were washed with water (2×20 ml), dried (MgSO4) and evaporated. The crude product was purified by flash chromatography on silica gel (dichloromethane/MeOH, 2-8%) and crystallization (dichloromethane/heptane) to yield the title compound as an off-white solid (50 mg, 31%), MS (ISP) m/z=373.4 [(M+H)+], mp 206° C.
