tert-Butyl 2-(4-(2-methyl-1H-imidazol-1-yl)phenylamino)-4-(trifluoromethylsulfonyloxy)-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate (250 mg, 0.45 mmol, example 69c) was dissolved in DMF (2 mL). (S)-indolin-2-ylmethanol (67.3 mg, 0.45 mmol) was added and the reaction mixture was heated at 85° C. overnight. The reaction was allowed to reach room temperature, the solvent was evaporated under reduced pressure and the crude was purified by flash column chromatography using dichloromethane and methanol as eluent and gave (S)-tert-butyl 4-(2-(hydroxymethyl)indolin-1-yl)-2-(4-(2-methyl-1H-imidazol-1-yl)phenylamino)-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate (65.3 mg, 26.2%). MS (ES+) m/z 554.4 (M+H)+
