Kolbe–Schmidt reaction involves the preparation of
ortho
‐ or
para
‐hydroxyl benzoic acid from carbon dioxide and sodium or potassium phenolate. This reaction is also known as the Kolbe–Schmidt carboxylation or Kolbe–Schmidt synthesis. It has been found that the sodium phenolate always contributes to the formation of
ortho
‐hydroxyl benzoic acid, whereas potassium phenolate often results in the production of
para
hydroxyl benzoic acid. The study finds that in most cases this reaction is feasible only with the highly activated phenols. This reaction is useful in the preparation of aromatic acids with strong electron‐donating groups.