A mixture of 10-chloro-7-(1-ethylpropyl)-2,3,4,5-tetrahydro-1H-[1,3]diazepino[1,2-a]benzimidazole (100.0 mg, 0.343 mmol), 4-bromo-1,6-dimethyl-1H-benzimidazole (154.9 mg), xantphos (20.0 mg, 0.0343 mmol), sodium tert-butoxide (40.0 mg, 0.412 mmol), tris(dibenzylideneacetone) dipalladium (31.0 mg, 0.0343 mmol) and toluene (2.0 mL) was stirred at 100° C. for 3 days. After cooling, the mixture was diluted with ethyl acetate and the precipitate was removed by filtration and the filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 0-80% ethyl acetate/n-hexane gradient mixture to give the mixture containing the title compound. The residue was purified by preparative HPLC to give the title compound as the trifluoroacetic acid salt. The salt was neutralized with aqueous sodium hydrogen carbonate and extracted with ethyl acetate. The extract was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo to give the title compound. The resulting solid was recrystallized from ethyl acetate/n-hexane to give the title compound as a colorless solid (51.0 mg, 0.117 mmol, 34%).
