p-Cresol

p-Cresol

Names
IUPAC name 4-Methylphenol
Other names 4-Hydroxytoluene, p-Hydroxytoluene, p-Methylphenol, 4-Cresol, p-Cresylic acid, 1-Hydroxy-4-methylbenzene
Identifiers
CAS Number	106-44-5 Y
ChEBI	CHEBI:17847 Y
ChEMBL	ChEMBL16645 Y
ChemSpider	13839082 Y
DrugBank	DB01688 Y
Jmol 3D model	Interactive image
KEGG	C01468 Y
RTECS number	GO6475000
UNII	1MXY2UM8NV Y
InChI InChI=1S/C7H8O/c1-6-2-4-7(8)5-3-6/h2-5,8H,1H3 Y Key: IWDCLRJOBJJRNH-UHFFFAOYSA-N Y InChI=1/C7H8O/c1-6-2-4-7(8)5-3-6/h2-5,8H,1H3 Key: IWDCLRJOBJJRNH-UHFFFAOYAN
SMILES Cc1ccc(O)cc1
Properties
Chemical formula	C7H8O
Molar mass	108.13
Appearance	colorless prismatic crystals
Density	1.0347 g/ml
Melting point	35.5 °C (95.9 °F; 308.6 K)
Boiling point	201.8 °C (395.2 °F; 474.9 K)
Solubility in water	2.4 g/100 ml at 40 °C 5.3 g/100 ml at 100 °C
Solubility in ethanol	fully miscible
Solubility in diethyl ether	fully miscible
Vapor pressure	0.11 mmHg (25°C)
Refractive index (nD)	1.5395
Vapor pressure	{{{value}}}
Related compounds
Related phenols	o-cresol, m-cresol, phenol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

para-Cresol, also 4-methylphenol, is an organic compound with the formula CH₃C₆H₄(OH). It is a colourless solid that is widely used intermediate in the production of other chemicals. It is a derivative of phenol, an isomer of o-cresol and m-cresol.

Production

Together with many other compounds, p-cresol is traditionally extracted from coal tar, the volatilized materials obtained in the roasting of coal to produce coke. This residue contains a few percent by weight of phenol and cresols. p-Cresol is currently prepared industrially mainly by a two step route beginning with the sulfonation of toluene:

CH₃C₆H₅ + H₂SO₄ → CH₃C₆H₄SO₃H + H₂O

Base hydrolysis of the sulfonate salt gives the sodium salt of the cresol:

CH₃C₆H₄SO₃Na + 2 NaOH → CH₃C₆H₄OH + Na₂SO₃ + H₂O

Other methods for the production of p-cresol include chlorination of toluene followed by hydrolysis. In the cymene-cresol process, phenol is alkylated with propylene to give p-cymene, which can be oxidatively dealkylated.

Applications

p-Cresol is mainly consumed in the production of antioxidants, e.g., butylated hydroxytoluene (BHT). The monoalkylated derivatives undergo coupling to give extensive family of diphenol antioxidants. These antioxidants are valued because they are relatively low in toxicity and nonstaining.

Natural occurrences

p-Cresol is a major component in pig odor.

p-Cresol is a component in human sweat. It is a component of human odor attractive to female mosquitoes.

Temporal glands secretion examination showed the presence of phenol and p-cresol during musth in male elephants.

p-Cresol is one of the very few compounds to attract the orchid bee Euglossa cyanura and has been used to capture and study the species.