Decarboxylation of Salicylic acid

I would like to know how and under what conditions can decarboxylation of salicylic acid (*o*-hydroxybenzoic acid) occur. I couldn't find any sources for it online. Here are some reasons I think it would happen:


1. The $\ce{COOH}$ group is out of plane of the benzene ring due to the *ortho* $\ce{OH}$ group, making it easier to decarboxylate.
2. The keto form is a beta keto-acid, which makes it easier to undergo decarboxylation.




From [(1)](http://dx.doi.org/10.1021/jo01032a016):



> 
> **Salicylic acid** decarboxylated to give phenol and carbon dioxide, at a convenient rate for kinetic measurements, at $200-230^\circ$, in a homogeneous solution of benzoic acid and certain other high-boiling solvents.
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> ... there was a considerable amount of interest in the possibility of a bimolecular decarboxylation mechanism involving an attack by a proton on the free acid or its anions. A variety of compounds such as anthracene-9-carboxylic acid, substituted cinnamic mesitoic acid, aminosalicylic acid, and **salicylic acid**, appeared to represent examples of this type of decarboxylation mechanism. In most cases, pseudo-first-order rate constants were
>  observed experimentally.
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> ... mechanism is also proposed for the decarboxylation of **salicylic acid** in benzoic acid solution. A competition between an oxygen atom and the terminal ring carbon atom for the proton to give either the undissociated acid or a $\sigma$-complex leading to products is shown by eq. 3. 
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> [![enter image description here](https://i.stack.imgur.com/rMDXc.png)](https://i.stack.imgur.com/rMDXc.png)
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> The effect of substituents on the rate of decarboxylation of **salicylic acid** has been used to support a bimolecular mechanism. Electron-donating groups in the *ortho* or *para* positions have led to an increase in rate. The increased electron density on the ring carbon atom bonded to the carboxyl group would presumably facilitate an attack by a proton at this position.
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> ... An attack by a proton on the terminal ring carbon atom of the **salicylate ion** would appear, at first glance, to be extremely unfavorable because of the close proximity of a formal negative charge. Any interaction should merely lead to undissociated acid. The hydroxyl group in the *ortho* position appears to influence the distribution of the charge because of the steric configuration.
>  Resonance and tautomeric forms, eq. 5, which do not involve an extensive shift of atoms, can be drawn which would distribute the charge in a manner favorable
>  to the proposed mechanism, eq. 3. 
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> [![enter image description here](https://i.stack.imgur.com/X9kos.png)](https://i.stack.imgur.com/X9kos.png)
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> This unique steric arrangement is not possible with *m*- or *p*-hydroxybenzoic acid, the effect of which is borne out by the fact that these two acids did not decarboxylate at a measurable rate in benzoic acid solution at $212^\circ$. Since inductive and resonance effects would be expected to be similar for the *ortho* and *para* isomers, the steric effect appears to exert a critical influence. 
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(1) Kaeding, W. W. *Oxidation of Aromatic Acids. IV. Decarboxylation of Salicylic Acids* J. Org. Chem. 1964, 29 (9), 2556–2559. [DOI: 10.1021/jo01032a016](http://dx.doi.org/10.1021/jo01032a016)


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