Editing Salicylic acid (section)

===Reactions===
Upon heating, salicylic acid converts to [[phenyl salicylate]]:<ref>{{cite journal |doi=10.1016/j.molcata.2004.03.057|title=Selective Synthesis of Phenyl Salicylate (Salol) by Esterification Reaction over Solid Acid Catalysts|year=2004| vauthors = Kuriakose G, Nagaraju N |journal=Journal of Molecular Catalysis A: Chemical |volume=223 |issue=1–2 |pages=155–159}}</ref><ref name=Ullmann/>

{{block indent|2{{nbsp}}HOC<sub>6</sub>H<sub>4</sub>CO<sub>2</sub>H  →  C<sub>6</sub>H<sub>5</sub>O<sub>2</sub>C<sub>6</sub>H<sub>4</sub>OH  +  CO<sub>2</sub>  +  H<sub>2</sub>O}}

Further heating gives [[xanthone]].<ref name=Ullmann/>

Salicylic acid as its conjugate base is a chelating agent, with an affinity for iron(III).<ref>{{cite journal |doi=10.1021/ic00168a070|title=Metal(III)-Salicylate Complexes: Protonated Species and Rate-Controlling Formation Steps|year=1983| vauthors = Jordan RB |journal=Inorganic Chemistry|volume=22|issue=26|pages=4160–4161}}</ref>

Salicylic acid slowly degrades to phenol and carbon dioxide at 200–230&nbsp;°C:<ref>{{cite journal | vauthors = Kaeding WW |title=Oxidation of Aromatic Acids. IV. Decarboxylation of Salicylic Acids |journal=The Journal of Organic Chemistry |date=1 September 1964 |volume=29 |issue=9 |pages=2556–2559 |doi=10.1021/jo01032a016}}</ref> 

{{block indent|C<sub>6</sub>H<sub>4</sub>OH(CO<sub>2</sub>H)  →  C<sub>6</sub>H<sub>5</sub>OH  +  CO<sub>2</sub>}}

All isomers of [[chlorosalicylic acid]] and of [[dichlorosalicylic acid]] are known.  5-Chlorosalicylic acid is produced by direct [[Chlorination reaction|chlorination]] of salicylic acid.<ref name=Ullmann/>