Toluene → 2-[4-(4-{4-[2-(1-tert-butylcarbamyl-pyrrolidin-2-yl)-3-(2-trimethylsilanyl-ethoxymethyl)-3H-imidazol-4-yl]-phenyl}-2-oxo-2H-pyridin-1-yl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 2-[5-[4-(2-Oxo-1,2-dihydro-pyridin-4-yl)-phenyl]-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (0.3027 g) in ethanol (5.0 mL) was added tetrabutylammonium hydroxide (0.375 mL of 1.5 M solution) and reaction mixture stirred for 1 hour., then concentrated to give a colorless oil. Residue was lyophilized from acetonitrile to give a yellow residue. To this residue was added 2-[4-Bromo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (0.301 g, prepared by reacting 2-(4-Bromo-1H-imidazol-2-yl)-pyrrolidine-1-carboxylic acid tert-butyl ester (prepared according to WO2008021927 A2) with 2-(trimethylsilyl)ethoxy]methyl chloride using sodium hydride in DMF) and mixture co-evaporated with toluene (15 mL). DMF (1.0 mL) and copper(I) iodide (0.035 g) were added and the reaction mixture was stirred at 95° C. for 24 hour, protected from light. To the reaction mixture was added tetrabutylammonium iodide (50 mg) and reaction continued for 2 days. Added more 2-[4-Bromo-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (0.35 g) and copper(I) iodide (0.050 g) and reaction continued for 24 hours. Reaction mixture was cooled and diluted with ethyl acetate and washed with 3N ammonium hydroxide. The aqueous layer was back-extracted with ethyl acetate (2×). The combined organic layer was washed with 3N ammonium hydroxide, H2O, brine and dried (MgSO4) then concentrated and purified by flash column chromatography (silica gel, 0 to 10% isopropanol/hexane) to give impure product that was repurified by preparative reverse phase HPLC (Gemini, 25 to 100% ACN/H2O+0.1% TFA). Product was lyophilized to give 2-[4-(4-{4-[2-(1-tert-butylcarbamyl-pyrrolidin-2-yl)-3-(2-trimethylsilanyl-ethoxymethyl)-3H-imidazol-4-yl]-phenyl}-2-oxo-2H-pyridin-1-yl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester (0.042 g): LCMS-ESI+: calc'd for C47H72N7O7Si2: 903.28 (M+H+). Found: 902.2, 903.2 (M+H+).

Provenance & Evidence