Acetaldehyde → 5-(Benzoxazol-2-yl)-1-cyclohexyl-2-methylbenzimidazole

Beteiligte Stoffe

Reaktionsschritte

2-(4-cyclohexylamino-3-nitrophenyl)benzoxazole (Working Example 16-1) (185 mg, 0.548 mmol) was added to a tetrahydrofuran (5 mL) solution including 10% palladium-carbon (50 mg), and a hydrogen atmosphere was substituted in the flask and this was stirred at room temperature for 5 hours. After the reaction was complete, this was filtered through Celite and the filtrate was concentrated. To a solution of the oil obtained in dimethylformamide (1.5 mL) was added a solution of acetaldehyde in dimethylformamide (approx. 2%, 1.35 mL, 0.586 mmol), water (0.1 mL), and oxone (117 mg, 0.190 mmol), and this was stirred at room temperature for 2.5 hours. After the reaction was complete, aqueous potassium carbonate solution was added, and this was extracted with ethyl acetate. The organic layer obtained was dried over anhydrous sodium sulfate, filtered, and concentrated to give an oil that was purified by silica gel column chromatography to yield the title compound (24.5 mg, 14% yield) as a light brown oil.

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