Sodium Thiosulfate → 2-Chloro-6-((4,6-dimethoxypyrimidin-2-yl)oxy)benzoic acid

Participants

Reaction Steps

To stirred solution of 9.6 grams (0.033 mole) of 6-chloro-2-(4,6-dimethoxypyrimidin-2-yloxy)benzaldehyde in 260 mL of acetone was added dropwise a solution of 7.7 grams (0.049 mole) of potassium permanganate and 6.6 grams (0.024 mole) of sodium phosphate dibasic heptahydrate in 105 mL of water while maintaining the reaction mixture temperature at 20°-25° C. Upon completion of addition, the reaction mixture was stirred at ambient temperature for 18 hours. After this time sodium thiosulfate was added to the reaction mixture to destroy excess permanganate. The reaction mixture was then filtered through diatomaceous earth. The filtrate was cooled and acidified to a pH of 3-4 with aqueous 10% hydrochloric acid. The mixture was extracted with two 50 mL portions of methylene chloride. The combined extracts were dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was crystallized from methylene chloride and carbon tetrachloride to yield 10.0 grams of 6-chloro-2 -(4,6-dimethoxypyrimidin-2-yloxy)benzoic acid. The nmr spectrum was consistent with the proposed structure.

Provenance & Evidence