Esterfication of 2,2,2-triphenylethanoic acid


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> Explain the formation of (1,1,1-triphenylmethyl)methyl ether when a solution of 2,2,2-triphenylethanoic acid in concentrated sulfuric acid is poured in methanol.
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I cannot figure out where is one carbon atom lost. Has it escaped as $\ce{CO2}$? Or is there something more strange happening.


I wouldn't call this reaction an esterification. There is no ester functional group in the final compound. 


I guess there's some special role of the three phenyl groups but I'm unable to come up with any mechanism. I hope dehydration is involved as one of the reaction steps.




**Disclaimer**: The question has pretty much been answered in the comments. I'm just making it substantial.


![mechanism](https://i.stack.imgur.com/bNk74.png)


The **triphenylacetic acid** is dehydrated in the presence of concentrated sulfuric acid to give an acylium ion, namely **triphenylacetylium cation**, which is stabilized by resonance.


Then, the triphenylacetylium cation undergoes decarbonylation (removal of carbon monoxide) to give **triphenylmethyl cation**, which is stabilized by the three phenyl groups.


The oxygen in methanol acts as a nucleophile to attack the carbocation, and is deprotonated to give our desired product **triphenylmethyl methyl ether**.


It is noted that this reaction should be done in a well-ventilated area because of the evolution of toxic carbon monoxide gas.


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