Sulfuric Acid → 1,2-Benzoxazole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

8.6 g of 3B was mixed with 175 ml of 70% sulfuric acid and the mixture was heated at 80° C. for 4 hours. The mixture was cooled, 200 ml of cold water was added, the mixture was extracted with ether, and the extract was dried (Na2SO4) and stripped of solvent. The residue was triturated with pentane, and the solid was collected and dried to give 3-benzisoxazolecarboxylic acid (3C), as a white solid, m.p.: 132°-134° C. (with decomposition).

Provenance & Evidence