Stir a suspension of {6-[2-tert-Butyl-5-(4-fluoro-phenyl)-3H-imidazol-4-yl]-3-nitro-pyridin-2-yl}-(2,2-dimethylpropyl)-amine (426 mg, 1.0 mmol) and 10% palladium on carbon (85 mg) in 100% ethanol under hydrogen from a balloon overnight. Filter the suspension through a 0.2 μm syringe filter and concentrate under reduced pressure. Dissolve the residue in 10% aqueous ethanol and treat at room temperature with cyanogen bromide (80 mg, 0.75 mmol, 1.5 equiv). When the reaction is complete, quench the reaction with saturated aqueous NaHCO3. Add ethyl acetate and water to dissolve all solids. Wash the organic layer once with saturated aqueous NaHCO3, once with saturated aqueous NaCl, dry with Na2SO4, filter, and concentrate under reduced pressure. Subject the residue to medium pressure silica gel chromatography eluting with 50% ethyl acetate/CH2Cl2 then with a gradient of 1.5-3.5% (2M ammonia in MeOH)/CH2Cl2) to provide 5-[2-tert-butyl-5-(4-fluoro-phenyl)-1H-imidazol-4-yl]-3-(2,2-dimethyl-propyl)-3H-imidazo[4,5-b]pyridin-2-ylamine as a brown foam (156 mg, 74% yield).
