Acetic Acid → N-benzyl-N-nitroso-2-cyclohexyl-2-[2-(2,6-dimethoxy-pyridin-3-yl)-5,6-difluoro-benzoimidazol-1-yl]-acetamide

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Reaction Steps

To an ice-cold solution of 15 g (28.81 mmol) N-benzyl-2-cyclohexyl-2-[2-(2,6-dimethoxy-pyridin-3-yl)-5,6-difluoro-benzoimidazol-1-yl]-acetamide in 94 ml (1642 mmol) acetic acid and 198 ml (3486 mmol) acetic anhydride were added in 5 portions over 30 min. 9.94 g (144 mmol) sodium nitrite. The resulting solution was allowed to warm to room temperature overnight. The resulting yellow suspension was evaporated and the yellow slurry was taken up in 500 ml saturated aqueous sodium bicarbonate solution and 1500 ml ethyl acetate. The aqueous layer was extracted twice with 1500 ml ethyl acetate and once with 500 ml ethyl acetate. The combined organic layers were washed with water and brine. The remaining unsoluble material was filtered off and the filtrate dried over magnesium sulfate, filtered and evaporated until a suspension has formed. This suspensions was filtered and the filter cake washed twice with 50 ml ice-cold ethyl acetate and dried in high vacuum. Light yellow solid. MS (Turbo Spray): m/z=550.3 [M+H].

Provenance & Evidence