A 16×100 mm vial was charged with 5-amino-2-methyl-N-(2-(4-(4-methylpiperazin-1-yl)phenylamino)pyrimidin-5-yl)benzamide 30 (0.100 g, 0.24 mmol), 4-(dimethylamino)pyridine (0.0059 g, 0.048 mmol), dichloromethane (2 mL), and diisopropylethylamine (0.050 ml, 0.29 mmol). A solution of mesityl carbonochloridate (0.048 g, 0.24 mmol) in dichloromethane (1 mL) was added dropwise and the reaction mixture stirred at room temperature for 20 hours. The reaction mixture was purified via column chromatography on silica gel (gradient elution with 0 to 20% methanol in dichloromethane) to afford mesityl 4-methyl-3-((2-(4-(4-methylpiperazin-1-yl)phenylamino)pyrimidin-5-yl)carbamoyl)phenylcarbamate 47 as a bright yellow solid.
