Potassium Carbonate → (1-{2-[4-(4-ethynyl-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester

Participants

Reaction Steps

A mixture of (1-{2-[5-(4-Bromo-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (364 mg, 0.81 mmol), Ethynyl-trimethyl-silane (0.68 mL, 4.9 mmol), Copper(I) iodide (154 mg, 0.81 mmol), tetrakis(triphenylphosphine)palladium (94 mg, 0.08 mmol) and triethylamine (0.67 mL, 4.9 mmol) in 5 ml DMF was heated to 70° C. overnight. The reaction mixture was cooled and dissolved in ethyl acetate and washed with 5% lithium chloride aqueous solution. The organic layer was dried (MgSO4), concentrated and purified by flash column chromatography (silica gel, 20 to 100% ethyl acetate/hexane) and followed by preparative reverse phase HPLC (GEMINI, 5 to 100% ACN/H2O+0.1% TFA) to give (2-Methyl-1-{2-[5-(4-trimethylsilanylethynyl-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-propyl)-carbamic acid methyl ester (324 mg). LCMS-ESI−: calc'd for C25H34BN4O3Si: 466.65. Found: 467.1 (M+H+). (1-{2-[5-(4-Ethyny]-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester: Potassium carbonate (192 mg) was added to (2-Methyl-1-{2-[5-(4-trimethylsilanylethynyl-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-propyl)-carbamic acid methyl ester (324 mg) in 7 mL MeOH solution. The reaction was stirred at room temperature overnight. The reaction mixture was concentrated down and purified by flash column chromatography (silica gel, 20 to 100% ethyl acetate/hexane) to give (1-{2-[5-(4-Ethynyl-phenyl)-1H-imidazol-2-yl]-pyrrolidine-1-carbonyl}-2-methyl-propyl)-carbamic acid methyl ester (234 mg).

Provenance & Evidence