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.[3]
o-Cresol
Kekulé, skeletal formula of o-cresol with some implicit hydrogens shown
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.[4]
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.[3]
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.[3]
^ abcdHelmut Fiegein "Cresols and Xylenols" in Ullmann's Encyclopedia of Industrial Chemistry" 2007; Wiley-VCH, Weinheim. doi:10.1002/14356007.a08_025
^The Beaver: Its Life and Impact. Dietland Muller-Schwarze, 2003, page 43 (book at google books)
^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. PMC3084482. PMID 21556207.
External linksedit
o-CRESOL (ICSC)
(accessed 22 December 2022)
CDC - NIOSH Pocket Guide to Chemical Hazards
January 01, 1970
cresol, orth, iupac, name, methylphenol, also, known, hydroxytoluene, ortho, toluenol, organic, compound, with, formula, ch3c6h4, colourless, solid, that, widely, used, intermediate, production, other, chemicals, derivative, phenol, isomer, cresol, cresol, kek. 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 3 o Cresol Kekule skeletal formula of o cresol with some implicit hydrogens shown Spacefill model of o cresol Names Preferred IUPAC name 2 Methylphenol Systematic IUPAC name 2 Methylbenzenol Other names 2 Cresolo Cresolortho Cresolortho Toluenolortho Benzol2 Hydroxytolueneo Cresylic acid1 Hydroxy 2 methylbenzene Identifiers CAS Number 95 48 7 Y 3D model JSmol Interactive image 3DMet B00313 Beilstein Reference 506917 ChEBI CHEBI 28054 Y ChEMBL ChEMBL46931 Y ChemSpider 13835772 Y ECHA InfoCard 100 002 204 EC Number 202 423 8 Gmelin Reference 101619 KEGG C01542 Y MeSH 2 Cresol PubChem CID 335 RTECS number GO6300000 UNII YW84DH5I7U Y UN number 2076 3455 CompTox Dashboard EPA DTXSID8021808 InChI InChI 1S C7H8O c1 6 4 2 3 5 7 6 8 h2 5 8H 1H3 YKey QWVGKYWNOKOFNN UHFFFAOYSA N N SMILES Cc1ccccc1O Properties Chemical formula C 7H 8O 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 Solubility in water 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 Magnetic susceptibility x 72 9 10 6 cm3 mol Refractive index nD 1 5353 Viscosity 35 06 cP at 45 C Thermochemistry Heat capacity C 154 56 J K 1 mol 1 Std molarentropy S 298 165 44 J K 1 mol 1 Std enthalpy offormation DfH 298 204 3 kJ mol 1 Std enthalpy ofcombustion DcH 298 3 6936 MJ mol 1 Hazards GHS labelling Pictograms Signal word Danger Hazard statements H301 H311 H314 Precautionary statements 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 320 Flash point 81 C 178 F 354 K Autoignitiontemperature 598 9 C 1 110 0 F 872 0 K Explosive limits 1 4 148 C 1 Lethal dose or concentration LD LC LD50 median dose 1350 mg kg rat oral 121 mg kg rat oral 344 mg kg mouse oral 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 Cresols m cresol p cresolbenzyl alcohol 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 Y N Infobox references Contents 1 Natural occurrences 2 Production 3 Applications 4 Health effects 5 References 6 External linksNatural occurrences edito 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 4 o Cresol is a constituent of tobacco smoke 5 Production editTogether 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 3 Applications edito 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 3 Health effects editMost 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 3 References edit a b c d NIOSH Pocket Guide to Chemical Hazards 0154 National Institute for Occupational Safety and Health NIOSH Cresol o m p isomers Immediately Dangerous to Life or Health Concentrations IDLH National Institute for Occupational Safety and Health NIOSH a b c d Helmut Fiegein Cresols and Xylenols in Ullmann s Encyclopedia of Industrial Chemistry 2007 Wiley VCH Weinheim doi 10 1002 14356007 a08 025 The Beaver Its Life and Impact Dietland Muller Schwarze 2003 page 43 book at google books 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 External links edito CRESOL ICSC Environmental Science SMILES Examples Notations accessed 22 December 2022 CDC NIOSH Pocket Guide to Chemical Hazards Retrieved from https en wikipedia org w index php title O Cresol amp oldid 1176433131, wikipedia, wiki, book, books, library,
