To a solution of 4-cyano-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazole-2-carboxylate potassium salt (296 mg, 0.970 mmol) (as prepared in Example 3, step (d)) in 8 mL DCM was added DIEA (291 μL, 1.72 mmol) and PyBroP (512 mg, 1.10 mmol), and the reaction was stirred at 25° C. for 15 min. A solution of 5-amino-6-cyclohex-1-enyl-3′,4′,5′,6′-tetrahydro-2′H-[2,4′]bipyridinyl-1′-carboxylic acid tert-butyl ester (233 mg, 0.65 mmol) (as prepared in the previous step) in 4 mL DCM was added and the reaction stirred overnight at 25° C. The reaction was diluted with EtOAc (25 mL) and washed with NaHCO3 (1×25 mL) and brine (25 mL) and the organic layer was dried over Na2SO4 and then concentrated. The residue was purified by flash chromatography (silica gel, 5% MeOH—CHCl3) to afford 167 mg (40%) of the title compound as a white solid. Mass Spectrum (ESI, m/z): Calcd. for C32H46N6O4Si, 607.3 (M+H). found 607.3.
