2,6-Dichlorophenol is a
compound with formula C
6H
3Cl
2OH. It is one of the six
isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
...
s of
dichlorophenol
Dichlorophenols (DCPs) are any of several chemical compounds which are derivatives of phenol containing two chlorine atoms. There are six isomers:
* 2,3-Dichlorophenol
* 2,4-Dichlorophenol
* 2,5-Dichlorophenol
* 2,6-Dichlorophenol
* 3,4-Dich ...
. It is a colorless solid. Its pK
a is 6.78, which is about 100x more acidic than
2-chlorophenol (8.52) and 1000x more acidic than phenol itself (9.95).
Preparation
It can be produced in a multistep process from
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it ...
, which is converted to its 4-sulfonic acid derivative. The resulting phenol sulfonic acid chlorinates at the positions flanking the phenol. Hydrolysis releases the sulfonic acid group.
An alternative synthesis starts with the ethyl ester of 4-hydroxybenzoic acid, which chlorinates at the positions flanking the phenolic center. Ester hydrolysis followed by
decarboxylation
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is ...
affords 2,6-dichlorophenol.
References
Chloroarenes
Phenols
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