3,4,5-Trifluorobenzonitrile → (+)-4-{2-[2-(4-Chloro-phenyl)-5,6-difluoro-benzoimidazol-1-yl]-2-cyclohexyl-1,1-dimethyl-ethoxy}-3,5-difluoro-benzonitrile

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Reaction Steps

A solution of 0.10 g (0.24 mmol) (−)-1-[2-(4-chloro-phenyl)-5,6-difluoro-benzoimidazol-1-yl]-1-cyclohexyl-2-methyl-propan-2-ol (Example 88, intermediate b) and 38 mg (0.24 mmol) 3,4,5-trifluorobenzonitrile in 2 ml anhydrous tetrahydrofuran was cooled down to 0° C. Then, 0.53 ml (0.26 mmol) potassium bis(trimethylsilyl)amide (0.5 M solution in toluene) were added dropwise to the reaction mixture. The cooling bath was removed and stirring was continued for 18 h. The reaction mixture was poured onto aqueous saturated ammonium chloride solution and the phases were separated. The aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by silica gel chromatography using a MPLC system (CombiFlash Companion, Isco Inc.) eluting with n-heptane for 5 min., then with a gradient of dichloromethane:ethyl acetate (100:0 to 95:5). Light brown foam (45%). MS (Turbo Spray): m/z=556.2 [M+H].

Provenance & Evidence