(1E,4E)-8-Bromo-2-(tert-butoxycarbonylamino)-3H-benzo[b]azepine-4-carboxylic acid (0.275 g, 0.721 mmol) was dissolved in 7 mls of dry DMF. To this solution was added HOBT (0.107 g, 0.794 mmol) and EDCI (0.152 mmol, 0.794 mmol), and this mixture was stirred at room temperature for 20 minutes. 3-Fluoro-N-propylpropan-1-amine hydrochloride (0.124 mmol, 0.794 mmol) followed by triethylamine (0.211 mls, 1.515 mmol) were then added and the reaction mixture stirred at room temperature for 16 hours. The mixture was then diluted with EtOAc, washed several times with brine, dried over sodium sulfate and concentrated under reduced pressure. Flash 40 Biotage (40S cartridge, 25% EtOAc/Hexane) afforded 0.089 g (26%) of tert-butyl (1E,4E)-8-bromo-4-((3-fluoropropyl)(propyl)carbamoyl)-3H-benzo[b]azepin-2-ylcarbamate. m/z (APCI-pos) M+1=481.8 and 483.8.
