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General procedure for the synthesis of 7-bromoquinazoline from quinazoline: Step A: N-bromosuccinimide (NBS, 2.13 g, 11.9 mmol) was slowly added to a solution of concentrated sulfuric acid (appropriate amount) of compound 214 (quinazoline, 1.04 g, 7.99 mmol) at room temperature. The reaction mixture was stirred continuously at room temperature for 16 h. The reaction progress was monitored by thin layer chromatography (TLC, unfolding agent: 5% methanol/dichloromethane) to confirm the completion of the reaction. Subsequently, the reaction mixture was carefully poured into crushed ice (~50 mL) and the pH was adjusted to neutral (pH=7) using ammonium hydroxide solution. The resulting slurry was continued to be stirred at 0 °C for 1 h. The solid product was then collected by filtration and washed with ice-cold water (3 x 30 mL). Finally, purification by silica gel column chromatography (SiO2, eluent: 5% methanol/dichloromethane) afforded the target compound 215 (7-bromoquinazoline) as a beige solid with a yield of 0.53 g in 32% yield. Product characterization: 1H NMR (400 MHz, DMSO-d6) δ 9.57 (s, 1H), 9.32 (s, 1H), 8.46 (d, 1H), 8.14 (dd, 1H), 7.96 (d, 1H).