1,2-Dimethoxyethane → (S)-2-[5-(2-{4-[2-((S)-1-tert-Butoxycarbonyl-pyrrolidin-2-yl)-3H-imidazol-4-yl]-phenyl}-pyrimidin-5-yl)-1-(2-trimethylsilanyl-ethoxymethyl)-1H-imidazol-2-yl]-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Pd(Ph3)4 (0.12 g, 0.103 mmol) was added in one portion to a stirred suspension of (S)-tert-butyl 2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (1c, 1.00 g, 2.27 mmol), (S)-tert-butyl 2-(5-(2-chloropyrimidin-5-yl)-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (152c-1, 0.99 g, 2.06 mmol) and NaHCO3 (0.87 g, 10.3 mmol) in a solution of DME (20 mL) and H2O (6 mL) at room temperature under N2. The vessel was sealed and the mixture was placed into a preheated (80° C.) oil bath and stirred at 80° C. for 16 h before additional catalyst (0.12 g) was added. After heating the mixture for an additional 12 h at 80° C., the mixture was cooled to ambient temperature, diluted with ethyl acetate and washed with sat'd NaHCO3 soln and brine prior to drying over anhydrous sodium sulfate and solvent concentration. Purification of the residue by Biotage™ flash chromatography on silica gel using a 40M column (preequilibrated with 40% B followed by step gradient elution with 40% B to 40% B for 150 mL, 40% B to 100% B for 1500 mL, 100% B to 100% B for 1000 mL where B=ethyl acetate and A=hexanes) furnished the title compound as a yellow foam (1.533 g, 98%). A small amount of the yellow foam was further purified for characterization purposes by pHPLC (Phenomenex GEMINI, 30×100 mm, S10, 10 to 100% B over 13 minutes, 3 minute hold time, 40 mL/min, A=95% water, 5% acetonitrile, 10 mM NH4OAc, B=10% water, 90% acetonitrile, 10 mM NH4OAc) to yield 95% pure title compound as a white solid.

Provenance & Evidence