Potassium Permanganate → 5-(4-(4-Cyanophenyl)piperidine-1-carbonyl)-2-methylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 4-(1-(3-formyl-4-methylbenzoyl)piperidin-4-yl)benzonitrile (compound 39.2, 600 mg, 1.81 mmol, 1.00 equiv) in THF (5 mL) was added dropwise a solution of KMnO4 (1 g) in water (10 mL). The resulting mixture was stirred overnight at 60° C. in an oil bath. After cooling to ambient temperature, the solids were removed by filtration and the pH of the filtrate was adjusted to ≧10 with sodium hydroxide (aqueous, 1 M). The resulting mixture was washed with 20 mL of ethyl acetate. Aqueous 1 M HCl was then employed to adjust the pH of the aqueous layer to ˜4. The resulting aqueous phase was extracted with 2×100 mL of ethyl acetate and the combined organic layers were dried over anhydrous sodium sulfate and concentrated under reduced pressure to yield 500 mg (80%) of the title compound as light yellow oil.

Provenance & Evidence