A solution of tert-butyl 2-[3-[bis(tert-butoxycarbonyl)amino]-6-bromo-pyrazin-2-yl]-6-methyl-benzimidazole-1-carboxylate (70 mg, 0.1158 mmol) in DMF (2 mL) was treated with thiomorpholine (59.74 mg, 0.5790 mmol) and heated to 60° C. for 3 hours. The mixture was then diluted with EtOAc, washed with water, brine, dried (MgSO4) and concentrated in vacuo. The residue was dissolved in DCM (10 mL), treated with mCPBA (59.95 mg, 0.3474 mmol) and stirred at RT for 1 hour. After washing with a 1:1 Na2CO3/Na2S2O3 solution, TFA (264.1 mg, 178.4 μL, 2.316 mmol) was added and the mixture stirred at RT for 1 hour. This was concentrated in vacuo and the resultant residue was purified by reverse phase preparative HPLC [Waters Sunfire C18, 10 uM, 100A column, gradient 10%-95% B (solvent A: 0.05% TFA in water, solvent B: CH3CN) over 16 minutes at 25 mL/min]. The fractions were collected and freeze-dried to give the title compound (13.1 mg, 31% Yield).
