PHENOLSPHENOLS

Mark Angelo N. SiguenzaMark Angelo N. Siguenza

John Robert C. JamesJohn Robert C. James

Daniel Thomas A. Daniel Thomas A. BerberabeBerberabe

Charles Jervis T. SyCharles Jervis T. Sy

PHENOLSPHENOLS

sometimes called sometimes called phenolicsphenolics, are a class , are a class of chemical compounds consisting of a of chemical compounds consisting of a hydroxyl group (-OH) bonded directly to an hydroxyl group (-OH) bonded directly to an aromatic hydrocarbon group. The simplest aromatic hydrocarbon group. The simplest of the class is phenol (C6H5OH).of the class is phenol (C6H5OH).

also known as also known as carbolic acidcarbolic acid, is a toxic, , is a toxic, white crystalline solid. Its chemical formula white crystalline solid. Its chemical formula is C6H5OH and its structure is that of a is C6H5OH and its structure is that of a hydroxyl group (-OH) bonded to a phenyl hydroxyl group (-OH) bonded to a phenyl ring, making it an aromatic compound.ring, making it an aromatic compound.

Although similar to alcohols, phenols have Although similar to alcohols, phenols have unique properties and are not classified as unique properties and are not classified as alcohols (since the hydroxyl group is not alcohols (since the hydroxyl group is not bonded to a bonded to a saturatedsaturated carbon atom). carbon atom).

They have relatively higher acidities due to They have relatively higher acidities due to the aromatic ring's tight coupling with the the aromatic ring's tight coupling with the oxygen and a relatively loose bond oxygen and a relatively loose bond between the oxygen and hydrogen.between the oxygen and hydrogen.

SYNTHESIS OF PHENOLSSYNTHESIS OF PHENOLS by an ester rearrangement in the Fries rearrangement by an ester rearrangement in the Fries rearrangement by a rearrangement of N-phenylhydroxylamines in the Bamberger by a rearrangement of N-phenylhydroxylamines in the Bamberger

rearrangement rearrangement by hydrolysis of phenolic esters or ethersby hydrolysis of phenolic esters or ethers by reduction of quinones by reduction of quinones by replacement of an aromatic amine by an hydroxyl group with by replacement of an aromatic amine by an hydroxyl group with

water and sodium bisulfide in the Bucherer reaction water and sodium bisulfide in the Bucherer reaction by hydrolysis of diazonium salts by hydrolysis of diazonium salts by oligomerisation with formaldehyde + base catalysed reaction with by oligomerisation with formaldehyde + base catalysed reaction with

epichlorohydrine to epoxi resin components epichlorohydrine to epoxi resin components by reaction with acetone/ketones to e.g. Bisphenol A, an important by reaction with acetone/ketones to e.g. Bisphenol A, an important

monomer for resins, e.g. polycarbonate(PC), epoxi resins monomer for resins, e.g. polycarbonate(PC), epoxi resins by a rearrangement reaction of dienones in the by a rearrangement reaction of dienones in the dienone phenol dienone phenol

rearrangementrearrangement

REACTION OF PHENOLSREACTION OF PHENOLS Esterfication reactions and ether formation Esterfication reactions and ether formation Electrophilic aromatic substitutions as the hydroxyl group is activating, for Electrophilic aromatic substitutions as the hydroxyl group is activating, for

example synthesis of calixarenes.example synthesis of calixarenes. Reaction of naphtols and hydrazines and sodium bisulfite in the Bucherer Reaction of naphtols and hydrazines and sodium bisulfite in the Bucherer

carbazole synthesis.carbazole synthesis. Oxidative cleavage, for instance cleavage of 1,2-dihydroxybenzene to the Oxidative cleavage, for instance cleavage of 1,2-dihydroxybenzene to the

monomethylester of 2,4 hexadienedioic acid with oxygen, copper chloride in monomethylester of 2,4 hexadienedioic acid with oxygen, copper chloride in pyridine.pyridine.

Oxidative de-aromatization to quinones also known as the Teuber reaction. Oxidative de-aromatization to quinones also known as the Teuber reaction. Oxidizing reagents are Fremy's salt and oxone. In reaction depicted below Oxidizing reagents are Fremy's salt and oxone. In reaction depicted below 3,4,5-trimethylphenol reacts with singlet oxygen generated from 3,4,5-trimethylphenol reacts with singlet oxygen generated from oxone/sodium carbonate in an acetonitrile/water mixture to a para-oxone/sodium carbonate in an acetonitrile/water mixture to a para-peroxyquinole. This hydroperoxide is reduced to the quinole with sodium peroxyquinole. This hydroperoxide is reduced to the quinole with sodium thiosulfate. thiosulfate.

Phenols are oxidized to phediols in the Elbs persulfate oxidation.Phenols are oxidized to phediols in the Elbs persulfate oxidation. Phenolate anions (deriving from phenols by the loss of H+) can act as Phenolate anions (deriving from phenols by the loss of H+) can act as

ligands towards metal cations ligands towards metal cations

NATURAL OCCURRENCENATURAL OCCURRENCE

Phenols are found in the natural world, Phenols are found in the natural world, especially in the plant kingdom. In some especially in the plant kingdom. In some cases phenols are present in vegetative cases phenols are present in vegetative foliage to discourage herbivory, such as in foliage to discourage herbivory, such as in the case of Western poison oak.the case of Western poison oak.

INDUSTRIAL PROCESSINGINDUSTRIAL PROCESSING

laboratory processes laboratory processes chemical industry chemical industry chemical engineering processes chemical engineering processes wood processing wood processing plastics processing plastics processing

MEDICINALSMEDICINALSCannabinoids the active constituents of cannabis

Diethylstilbestrol a synthetic estrogen with a stilbene structure

L-DOPA a dopamine prodrug

Methyl salicylate the major constituent of the essential oil of wintergreen

Propofol a short-acting intravenous anesthetic agent

Salicylic acida plant hormone used for its analgesic, antipyretic, and anti-inflammatory properties, also

a precursor compound to Aspirin

PROPERTIESPROPERTIES

Molecular formula------------------------Molecular formula------------------------C6H5OHC6H5OH Molar mass------------------------------Molar mass------------------------------94.11 g/mol94.11 g/mol Appearance---------------Appearance---------------White Crystalline SolidWhite Crystalline Solid Density--------------------------------------Density--------------------------------------1.07 g/cm³1.07 g/cm³ Melting point--------------Melting point--------------40.5 °C, 314 K, 105 °F40.5 °C, 314 K, 105 °F Boiling point-------------Boiling point-------------181.7 °C, 455 K, 359 °F181.7 °C, 455 K, 359 °F Solubility in water-----------Solubility in water-----------8.3 g/100 ml (20 °C)8.3 g/100 ml (20 °C) Acidity (pKa)---------------------------------------Acidity (pKa)---------------------------------------9.959.95 Dipole moment----------------------------------Dipole moment----------------------------------1.7 D1.7 D