Salicylic Acid Synthesis Methods: A Review

Published data on salicylic acid synthesis methods based on the use of phenol, ortho-cresol, and benzoic acid are reviewed and analyzed. Current trends in the development of a technology based on the Kolbe–Schmitt process (production of aromatic and heteroaromatic hydroxy acids by treating alkali metal phenolates with CO₂) are shown. Data on the effect of the catalyst system composition and benzoic acid hydroxylation process conditions on the achieved conversion and selectivity values and purity of the product are described. The review can be useful for choosing a suitable raw material base and a precursor conversion method for the development of domestic production of salicylic acid, which is a high-demand compound used in various industries.