o-Cresol (Redirected from O-cresol)

Kekulé, skeletal formula of o-cresol with some implicit hydrogens shown
Kekulé, skeletal formula of o-cresol with some implicit hydrogens shown
Spacefill model of o-cresol
Spacefill model of o-cresol
Preferred IUPAC name
Systematic IUPAC name
Other names
o-Cresylic acid
3D model (JSmol)
ECHA InfoCard 100.002.204 Edit this at Wikidata
EC Number
  • 202-423-8
MeSH 2-Cresol
RTECS number
  • GO6300000
UN number 2076, 3455
  • InChI=1S/C7H8O/c1-6-4-2-3-5-7(6)8/h2-5,8H,1H3 checkY
  • Cc1ccccc1O
Molar mass 108.140 g·mol−1
Appearance Colorless to white crystals
Odor sweet, phenolic odor
Density 1.0465 g cm−3
Melting point 31 °C; 88 °F; 304 K
Boiling point 191 °C; 376 °F; 464 K
31 g dm−3 (at 40 °C)
Solubility soluble in chloroform, ether, CCl4
Solubility in ethanol Miscible (at 30 °C)
Solubility in diethyl ether Miscible (at 30 °C)
log P 1.962
Vapor pressure 40 Pa (at 20 °C)
Acidity (pKa) 10.316
Basicity (pKb) 3.681
−72.9×10−6 cm3/mol
Viscosity 35.06 cP (at 45 °C)
154.56 J K−1 mol−1
165.44 J K−1 mol−1
−204.3 kJ mol−1
−3.6936 MJ mol−1
GHS labelling:
GHS05: CorrosiveGHS06: Toxic
H301, H311, H314
P260, P264, P270, P280, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P361, P363, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
Flash point 81 °C (178 °F; 354 K)
598.9 °C (1,110.0 °F; 872.0 K)
Explosive limits 1.4%–? (148 °C)
Lethal dose or concentration (LD, LC):
1350 mg/kg (rat, oral)
121 mg/kg (rat, oral)
344 mg/kg (mouse, oral)
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 5 ppm (22 mg/m3) [skin]
REL (Recommended)
TWA 2.3 ppm (10 mg/m3)
IDLH (Immediate danger)
250 ppm
Safety data sheet (SDS) External MSDS
Related compounds
Related phenols
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

ortho-Cresol (IUPAC name: 2-methylphenol, also known as 2-hydroxytoluene or ortho-Toluenol) 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 and is an isomer of p-cresol and m-cresol.

Natural occurrences

o-Cresol is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's castor glands and found in the white cedar consumed by the beaver.

o-Cresol is a constituent of tobacco smoke.


Together with many other compounds, o-cresol is traditionally extracted from coal tar, the volatile materials obtained in the production of coke from coal. A similar source material is petroleum residues. These residue contains a few percent by weight of phenol and isomeric cresols. In addition to the materials derived from these natural sources, about two thirds of the Western world's supply is produced by methylation of phenol using methanol. The alkylation is catalysed by metal oxides:

C6H5OH + CH3OH → CH3C6H4OH + H2O

Over-methylation gives xylenol. Many other production methods have been examined, including oxidative decarboxylation of salicylic acid, oxygenation of toluene, and hydrolysis of 2-chlorotoluene.


o-Cresol is mainly used as a precursor to other compounds. Chlorination and etherification gives members of commercially important herbicides, such as 2-methyl-4-chlorophenoxyacetic acid (MCPA). Nitration gives dinitrocresol, a popular herbicide. Kolbe–Schmitt carboxylation gives o-cresotinic acid, a pharmaceutical intermediate. Carvacrol, essence of oregano, is derived by alkylation of o-cresol with propene. The muscle relaxant mephenesin is an ether derived from o-cresol.

Health effects

Most exposures to cresols are at very low levels that are not harmful although, like phenols, cresols are skin irritants. When cresols are inhaled, ingested, or applied to the skin at very high levels, they can be harmful. Breathing high levels of cresols for a short time results in irritation of the nose and throat. Aside from these effects, very little is known about the effects of breathing cresols at lower levels over longer times. The acute LD50 for oral ingestion by mice is 344 mg/kg.

This page was last updated at 2024-03-03 10:16 UTC. Update now. View original page.

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