Hydrochloric Acid → N-benzyl-2-[2-(4-chloro-phenyl)-5,6-difluoro-benzoimidazol-1-yl]-2-(4,4-difluoro-cyclohexyl)-acetamide

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Reaction Steps

To a solution of 3.8 g (15.56 mmol) (2-amino-4,5-difluoro-phenyl)-carbamic acid tert-butyl ester (Example 73, intermediate g) in 38 ml methanol, 2.54 g (17.12 mmol) 4,4-difluorocyclohexanone (commercially available) were added. After stirring for 5 min. at room temperature the solution was treated with 2.44 g (15.58 mmol) p-chlorobenzoic acid, followed by an addition of 1.9 ml (15.56 mmol) benzyl isocyanide (commercially available). To the viscous slurry 12 ml methanol were added and the reaction for 22.5 h. Then 19.45 ml (77.80 mmol) 4M hydrochloric acid in dioxane were added dropwise over 5 min. After 4.5 h another 19.45 ml (77.80 mmol) 4M hydrochloric acid in dioxane were added. After 24 h, the suspension was poured onto 300 ml aqueous saturated sodium bicarbonate solution and the phases were separated. The aqueous layer was extracted three times with ethyl acetate and the 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 a gradient of heptane:ethyl acetate (100:0 to 50:50). Light yellow solid (76%). MS (Turbo Spray): m/z=530.2 [M+H].

Provenance & Evidence