Propylene Oxide → 10-Bromo-6-methyl-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine

To a solution of 2-(5-bromo-2-fluoro-phenyl)-1H-imidazole (250 mg, 1.0371 mmol) in dimethylformamide (3.0 mL) was added sodium hydride (1.1 equiv., 45.6 mg, 1.1408 mmol) at 0° C. The reaction was stirred at this temperature for 10 minutes, then (+/−)-propylene oxide (1.2 equiv., 0.09 mL, 1.2445 mmol) was added and the mixture was allowed to warm up to room temperature. The reaction was then heated to 95° C. for 6 h. The reaction mixture was cooled to room temperature and quenched with saturated aqueous ammonium chloride. The solution was extracted 3× with methylene chloride. The organic layers were combined, dried with sodium sulfate, and concentrated in vacuo. The crude was purified by flash chromatography (5-100% EtOAc in heptanes) to afford 188 mg (65% yield) of an orange solid.