Sodium Carbonate → 8-Hydroxy-5-sulfoquinoline-7-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

The 7-formyl-8-hydroxyquinoline-5-sulfonic acid (15 mmol, 3.80 g) was dissolved in sodium carbonate solution (34.5 mmol, 3.66 g in 200 mL of H2O). The solution was stirred and heated at 52° C. (oil bath). Then to the hot solution potassium permaganate (37.5 mmol, 5.94 g) was added. The temperature was increased to 68° C. The stirring and heating (60°-65° C.) was continued for 55 minutes. After that time the reaction mixture was filtered, and the solid was washed with sodium carbonate solution followed by water. The filtrate was concentrated under reduced pressure, acidified with 50% sulfuric acid (pH 3) and left for crystallization. The precipitate was filtered off, washed with a small amount of water and dried to give 1.96 g of 7-carboxy-8-hydroxyquinoline-5-sulfonic acid (48.5%).

Provenance & Evidence