tert-Butyl 2-[3-[bis(tert-butoxycarbonyl)amino]-6-bromo-pyrazin-2-yl]-6-methyl-benzimidazole-1-carboxylate (1000 mg, 1.654 mmol), iodocopper (31.50 mg, 0.1654 mmol), Pd(PPh3)4 (191.1 mg, 0.1654 mmol), triethylamine (836.8 mg, 1.153 mL, 8.270 mmol) and prop-2-yn-1-amine (182.2 mg, 3.308 mmol) were stirred in DMF (5 mL) at ambient temperature for 2 hours. The reaction mixture was diluted with ethyl acetate the organic layer washed with water, brine, dried (MgSO4), and concentrated in vacuo. The residue was purified by column chromatography eluting with 25/75 ethyl acetate/petroleum ether to give the sub-title compound as an off-white solid which was used directly in the next step with out further purification.
