To a solution of tert-butyl 4-(5-methyl-2-((4-((1-methylpiperidin-4-yl)carbamoyl)-2-nitrophenyl)amino)pyrimidin-4-yl)piperazine-1-carboxylate (0.073 g, 0.13 mmol) in DCM (1.0 mL) was added TFA (1.0 mL) and the mixture was stirred for 1 h. An aliquot of the reaction mixture was analyzed by LCMS, which indicated that the reaction had proceeded to completion. The solvents were removed and the residue was dried on high vacuum. The crude product was used for the next step without further purification. To a solution of 4-((5-methyl-4-(piperazin-1-yl)pyrimidin-2-yl)amino)-N-(1-methylpiperidin-4-yl)-3-nitrobenzamide (0.073 mmol) in DCM (1.5 mL) was added 4-isocyanatobenzonitrile (23 mg, 0.16 mmol) and triethylamine (0.055 mL, 0.39 mmol) and the mixture was stirred at 23° C. for 16 h. reaction. The crude reaction mixture was filtered and washed with minimal volume of DCM and then hexanes to give the title compound (97 mg, 100%). MS (ES+) C30H34N10O4 requires: 598. found: 599 [M+H]+
