45 mg (0.17 mmol) of 4-[(3-ethyl-1H-pyrrolo[2,3-b]pyridin-4-yl)oxy]-3-fluoroaniline and 34 mg (0.17 mmol) of 4-chloro-6-trifluoromethyl)pyrimidine-2-amine are suspended in 5 ml of water. 24 μl of 37% strength hydrochloric acid are added, and the mixture is heated at reflux overnight. Another 70 mg (0.35 mmol) of 4-chloro-6-(trifluoromethyl)pyrimidine-2-amine and 40 μl of 37% strength hydrochloric acid are then added, and the mixture is heated at reflux for another night. Using 1N aqueous sodium hydroxide solution, the pH is then adjusted to 10. The mixture is concentrated under reduced pressure and the residue is purified by column chromatography on silica gel (mobile phase: dichloromethane/methanol 100:1 to 10:1). The product obtained is purified further by preparative HPLC.
