Potassium Permanganate → 3-Amino-6-chloro-4-methylpicolinic acid

Participants

Reaction Conditions

Reaction Steps

3-Amino-6-chloro-2-(2-furanyl)-4-methylpyridine (400 mg) was dissolved in acetone (10 mL) and cooled in an ice bath to 0° C. A solution prepared of potassium permanganate (909 mg) in water (15 mL) was added drop wise to this solution. After complete addition, the reaction mixture was allowed to warm to room temperature and stirred for 2 hours. The mixture was cooled again to 0° C. and a second portion of potassium permanganate (600 mg) in water (10 mL) was added and the cool bath removed. After stirring for 2 hours, the reaction mixture was filtered through a pad of celite, the filter cake was washed carefully with water, methanol and ethyl acetate and concentrated to approx. 10 mL on a rotary evaporator. 2N Sodium hydroxide solution was added to adjust the pH-value to −12 and the aqueous layer was washed 2× with MTB-ether. The aqueous layer was then adjusted to pH ˜2 by addition of 6N hydrochloric acid and extracted 3× with MTB-ether. The combined organic layer was washed with brine, dried over MgSO4 and concentrated in vacuum to afford 262 mg of the title compound of the formula

Provenance & Evidence