100 mg (0.22 mmol) of 1-(6-bromo-pyridin-2-ylmethyl)-3-(6-chloro-pyridine-3-carbonyl)-1H-quinolin-4-one and 72 mg (1.1 mmol) of sodium azide were heated at 100° C. in 1 mL of DMF for 1 h. The temperature of the solution was lowered to 70° C. and 1 mL of water was added, followed by 214 uL (155 mg, 1.54 mmol) of triethylamine and 378 mg (1.32 mmol) of tris(2-carboxyethyl)phosphine hydrochloride. After 1 h of reaction time the mixture was purified on reverse-phase HPLC, followed by flash chromatography to give 60 mg of a yellow powder. LC-MSD, m/z for C21H15BrN4O2 [M+H]+=435.0, 437.0; HPLC retention time: 0.6 min.
