M-Cresol

Not to be confused with Metacresol purple.

meta-Cresol, also 3-methylphenol, is an organic compound with the formula CH₃C₆H₄(OH). It is a colourless, viscous liquid that is used as an intermediate in the production of other chemicals. It is a derivative of phenol and is an isomer of p-cresol and o-cresol.^[3]

m-Cresol

Names
IUPAC name 3-methylphenol
Other names 3-Cresol m-Cresol 3-Hydroxytoluene m-Cresylic acid 1-Hydroxy-3-methylbenzene 3-Methylbenzenol
Identifiers
CAS Number	108-39-4 Y
3D model (JSmol)	Interactive image
Beilstein Reference	506719
ChEBI	CHEBI:17231 N
ChEMBL	ChEMBL298312 N
ChemSpider	21105871 N
DrugBank	DB01776 N
ECHA InfoCard	100.003.253
EC Number	203-39-4
Gmelin Reference	101411
KEGG	C01467
PubChem CID	342
RTECS number	GO6125000
UNII	GGO4Y809LO N
CompTox Dashboard (EPA)	DTXSID6024200
InChI InChI=1S/C7H8O/c1-6-3-2-4-7(8)5-6/h2-5,8H,1H3 N Key: RLSSMJSEOOYNOY-UHFFFAOYSA-N N InChI=1/C7H8O/c1-6-3-2-4-7(8)5-6/h2-5,8H,1H3 Key: RLSSMJSEOOYNOY-UHFFFAOYAJ
SMILES Cc1cc(O)ccc1
Properties
Chemical formula	C7H8O
Molar mass	108.14 g/mol
Appearance	colorless liquid to yellowish liquid
Density	1.034 g/cm3, liquid at 20 °C
Melting point	11 °C (52 °F; 284 K)
Boiling point	202.8 °C (397.0 °F; 475.9 K)
Solubility in water	2.35 g/100 ml at 20 °C 5.8 g/100 ml at 100 °C
Solubility in ethanol	miscible
Solubility in diethyl ether	miscible
Vapor pressure	0.14 mmHg (20 °C)[1]
Magnetic susceptibility (χ)	−72.02×10−6 cm3/mol
Refractive index (nD)	1.5398
Viscosity	6.1 cP at 40 °C
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	May cause serious burns. Very destructive of mucous membranes. Harmful if inhaled. Toxic in contact with the skin or if swallowed.
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H227, H301, H311, H314, H351, H370, H372, H373, H401
Precautionary statements	P201, P202, P210, P260, P264, P270, P273, P280, P281, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P307+P311, P308+P313, P310, P312, P314, P321, P322, P330, P361, P363, P370+P378, P403+P235, P405, P501
NFPA 704 (fire diamond)	3 2 0
Flash point	86 °C
Explosive limits	1.1%–? (149 °C)[1]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	242 mg/kg (oral, rat, 1969) 2020 mg/kg (oral, rat, 1944) 828 mg/kg (oral, mouse)[2]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 5 ppm (22 mg/m3) [skin][1]
REL (Recommended)	TWA 2.3 ppm (10 mg/m3)[1]
IDLH (Immediate danger)	250 ppm[1]
Safety data sheet (SDS)	External MSDS
Related compounds
Related phenols	o-cresol, p-cresol, phenol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Production

Together with many other compounds, m-cresol is traditionally extracted from coal tar, the volatile materials obtained in the production of coke from (bituminous) coal. This residue contains a few percent by weight of phenol and isomeric cresols. In the cymene–cresol process, toluene is alkylated with propylene to give isomers of cymene, which can be oxidatively dealkylated analogous to the cumene process. Another method, involves carbonylation of a mixture of methallyl chloride and acetylene in the presence of nickel carbonyl.^[3]

Applications

m-Cresol is a precursor to numerous compounds. Important applications include:

• pesticides such as fenitrothion and fenthion
• synthetic vitamin E by methylation to give 2,3,6-trimethylphenol^[3]
• antiseptics, such as amylmetacresol
• a solvent for polymers. For example, polyaniline is cast from a solution of m-cresol to form a polyaniline film with a superior conductivity than polyaniline alone. This phenomenon is known as secondary doping.^[4]
• preservatives in some insulin preparations
• the starting point in the total synthesis of thymol,^[5] an important synthetic chemical for regions lacking natural sources of the flavor compound:^[6]

C₇H₈O + C₃H₆ ⇌ C₁₀H₁₄O

• synthesis of dicresulene and policresulen^{[citation needed]}
• synthesis of toliprolol, tolamolol & cresatin^{[citation needed]}

Natural occurrences

m-Cresol is a component found in temporal glands secretions during musth in male African elephants (Loxodonta africana).^[7]

m-Cresol is a constituent of tobacco smoke.^[8]

m-Cresol is a component found in secretions from the ant Colobopsis saundersi during Autothysis.^{[9] [10]}

See also

• Cresol

References

1. NIOSH Pocket Guide to Chemical Hazards. "#0155". National Institute for Occupational Safety and Health (NIOSH).
2. "Cresol (o, m, p isomers)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
3. Helmut Fiege (2007). "Cresols and Xylenols". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_025. ISBN 978-3527306732.
4. Alan G. MacDiarmid and Arthur J. Epstein. 1995. "Secondary Doping in Polyaniline" Synthetic Metals 69 (85-92).
5. Stroh, R.; Sydel, R.; Hahn, W. (1963). Foerst, Wilhelm (ed.). Newer Methods of Preparative Organic Chemistry, Volume 2 (1st ed.). New York: Academic Press. p. 344. ISBN 9780323150422.
6. Asim Kumar Mukhopadhyay (2004). Industrial Chemical Cresols and Downstream Derivatives. New York: CRC Press. pp. 99–100. ISBN 9780203997413.
7. Some chemical constituents of the secretion from the temporal gland of the African elephant (Loxodonta africana). Jack Adams, Alexander Garcia and Christopher S. Foote, Journal of Chemical Ecology, 1978, Volume 4, Number 1, 17-25, doi:10.1007/BF00988256
8. Talhout, Reinskje; Schulz, Thomas; Florek, Ewa; Van Benthem, Jan; Wester, Piet; Opperhuizen, Antoon (2011). "Hazardous Compounds in Tobacco Smoke". International Journal of Environmental Research and Public Health. 8 (12): 613–628. doi:10.3390/ijerph8020613. ISSN 1660-4601. PMC 3084482. PMID 21556207.
9. Jones, T. H.; Clark, D. A.; Edwards, A. A.; Davidson, D. W.; Spande, T. F.; Snelling, Roy R. (2004). "The chemistry of exploding ants, Camponotus spp. (cylindricus complex)". Journal of Chemical Ecology. 30 (8): 1479–1492. doi:10.1023/B:JOEC.0000042063.01424.28. PMID 15537154. S2CID 23756265.
10. Betz, Oliver (2010). "Adhesive Exocrine Glands in Insects: Morphology, Ultrastructure, and Adhesive Secretion". In von Byern, Janek; Grunwald, Ingo (eds.). Biological Adhesive Systems. pp. 111–152. doi:10.1007/978-3-7091-0286-2_8. ISBN 978-3-7091-0141-4.

External links

• NIOSH Pocket Guide to Chemical Hazards cdc.gov
• Chemical and physical properties chemicalbook.com