(5-Bromo-pyridin-2-yl)-(2,4-difluoro-phenyl)-amine (3 g; 10.5 mmol) is dissolved in THF (70 ml) and cooled to −78 C. nBuLi (14.5 ml of a 1.5M solution in hexane; 23 mmol) is added dropwise and the resulting yellow suspension stirred or 20 min. 5-Bromo-2-chlorobenzaldehyde in THF (6 ml) is added at −78 C. After 5 min at −78 C, the reaction mixture is warmed to −50 C, poured on water and extracted with TBME twice. The combined organic phases are dried over Na2SO4 and evaporated to dryness. Purification via chromatography (SiO2; acetone/hexanes 6/94>12/88) yields the title compound as orange viscuous oil, (2.58 g; 58%) which is used in the next step. b) (5-Bromo-2-chloro-phenyl)-[6-(2,4-difluoro-phenylamino)-pyridin-3-yl]-methanone
