2,6-Dichlorophenol is a

compound Compound may refer to: Architecture and built environments * Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall ** Compound (fortification), a version of the above fortified with defensive struct ...

with formula C₆H₃Cl₂OH. 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. Iso ...

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 req ...

, 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 t ...

affords 2,6-dichlorophenol.

References

Chloroarenes Phenols {{organohalide-stub