A mixture of 2-morpholinoacetic acid (0.034 g, 0.24 mmol), DIEA (0.165 mL, 0.94 mmol) and PyBOP® (0.125 g, 0.24 mmol) in CH2Cl2 (1 mL) was stirred at RT for 10 minutes, upon which it was added to a solution of tert-Butyl 5-(2-(3-aminophenyl)-7-methoxy-6-(2-methoxyethoxy)quinazolin-4-ylamino)-1H-indazole-1-carboxylate (0.260 g, 0.47 mmol) in CH2Cl2 (10 mL), the subsequent was stirred at RT for 1 hr upon which further aliquots of 2-morpholinoacetic acid (0.034 g, 0.24 mmol) and PyBOP® (0.125 g, 0.24 mmol) were added. The resulting mixture was stirred at RT overnight upon which the mixture was concentrated in vacuo and taken directly to the next step. HPLC retention time 5.35 mins.
