Tetrakis(triphenylphosphine)palladium(0) (0.0797 g, 0.000069 mol) was added to a solution of 0.50 M of cyclopropylzinc bromide in tetrahydrofuran (4.1 mL) and N-(3-bromo-6-fluoro-imidazo[1,2-a]pyridin-2-yl)-2,2,2-trifluoro-acetamide (compound d, 0.225 g, 0.000690 mol) in tetrahydrofuran (20.0 mL) and the reaction was heated to reflux for 3 hours. An additional 0.50 M of cyclopropylzinc bromide (4.1 mL) in tetrahydrofuran and tetrakis(triphenylphosphine)palladium(0)(0.080 g) was added and the mixture was heated to reflux overnight. The reaction was concentrated in vacuo and crude product purified by column chromatography (50% ethyl acetate/hexanes) to give N-(3-cyclopropyl-6-fluoro-imidazo[1,2-a]pyridin-2-yl)-2,2,2-trifluoro-acetamide as a yellow solid. Rf 0.46, 50% ethyl acetate/hexanes; MS m/z 287 (M+H).
