Ethanol → 5-Acetyl-1-[3-(1-methylpiperidin-3-yl)phenyl]benzimidazole

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-acetyl-N-[3-(1-methyl-1,2,3,6-tetrahydropyrid-5-yl)phenyl]-2-nitroaniline (6, Ex. 12a) (1 g, 3 mmol) in ethanol (50 ml) was added a catalytic amount of palladium on charcoal and the mixture was hydrogenated at ambient pressure over night. The reaction mixture was filtered through celite and the filtrate was concentrated under reduced pressure. To this concentrate formic acid (10 ml) was added and the resulting solution was stirred at 80° C. over night. Excess formic acid was removed by evaporation. The residue was dissolved in water and rendered alkaline by addition of solid sodium carbonate. Extraction with ethyl acetate and treatment of the extract with activated carbon in ethanol afforded 5-acetyl-1-[3-(1-methylpiperidin-3-yl)phenyl]-benzimidazole (9) (0.5 g, 50%) as an oil. m/e 333.

Provenance & Evidence