2-Chlorophenylhydrazine hydrochloride → 9-bromo-2-(1-(2-chlorophenyl)-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine

To a solution of 9-bromo-N-formyl-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine-2-carboxamide (350 mg, 1.04 mmol) in HOAc (10 ml) was added (2-chlorophenyl)hydrazine hydrochloride (557 mg, 3.13 mmol) in one portion. The resulting mixture was stirred at 80° C. for 4 h. The reaction mixture was cooled to room temperature and concentrated. The residue was dissolved in MeOH and purified by chromatography on silica gel (Hexanes:EtOAc=10:1-1:1) to give 9-bromo-2-(1-(2-chlorophenyl)-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine (300 mg, 65%). LCMS (ESI): m/z 443.7 (M+H+)