PROCESS FOR THE SEPARATION OF NITROTOLUIC ACID ISOMERS

摘要

A process for separately isolating 3-nitro-o-toluic acid and 5-nitro-o-toluic acid from a mixture of both, which comprises adding an aromatic organic base such as aniline or pyridine to the mixture to form the corresponding salts, throwing the salts into water or a solvent mixture comprising water and a water-soluble organic compound such as methanol, subjecting the resulting mixture to solid-liquid separation by utilizing the difference between the salts in the solubility in water or the solvent mixture, and recovering 3-nitro-o-toluic acid and 5-nitro-o-toluic acid from the resulting solution and solid, respectively.