Xylenols are organic compounds with the formula (CH3)2C6H3OH. They are volatile colorless solids or oily liquids. They are derivatives of phenol with two methyl groups at various positions relative to the hydroxyl group. Six isomers exist, of which 2,6-xylenol with both methyl groups in an ortho position with respect to the hydroxyl group is the most important. The name xylenol is a portmanteau of the words xylene and phenol.
2,4-Dimethylphenol together with other xylenols and many other compounds are traditionally extracted from coal tar, the volatile materials obtained in the production of coke from coal. These residue contains a few percent by weight of xylenols as well as cresols and phenol. The main xylenols in such tar are the 3,5-, 2,4, and 2,3- isomers. 2,6-Xylenol is produced by methylation of phenol using methanol in the presence of metal oxide catalysts: [1]
Typically, xylenols also ethylphenols, which have very similar physical properties. [2]
The physical properties of the six isomeric xylenols are similar.
| Isomer | 2,6-Xylenol | 2,5-Xylenol | 2,4-Xylenol | 2,3-Xylenol | 3,4-Xylenol | 3,5-Xylenol |
| Structure |  |  |  |  |  |  |
| CAS | 576-26-1 | 95-87-4 | 105-67-9 | 526-75-0 | 95-65-8 | 108-68-9 |
| Mp °C | 43-45 | 63 - 65 | 22-23 | 70-73 | 62 - 68 | 61-64 |
| Bp °C | 203 | 212 | 211-212 | 217 | 227 | 222 |
| pKa [3] | 10.59 | 10.22 | 10.45 | 10.50 | 10.32 | 10.15 |
| Density g/mL | 0.971 | 1.011 | ||||
Together with cresols and cresylic acid, xylenols are an important class of phenolics with great industrial importance. They are used in the manufacture of antioxidants. Xylenol orange is a redox indicator built on a xylenol skeleton. 2,6-Xylenol is a monomer for poly(p-phenylene oxide) (PEO) engineering resins through carbon-oxygen oxidative coupling.
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (—OH) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, C
6H
5OH. Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule.
Cresols are a group of aromatic organic compounds. They are widely-occurring phenols which may be either natural or manufactured. They are also categorized as methylphenols. Cresols commonly occur as either solids or liquids because their melting points are generally close to room temperature. Like other types of phenols, they are slowly oxidized by exposure to air, and the resulting impurities often give the samples a yellow to brownish red tint. Cresols have an odor characteristic to that of other simple phenols, reminiscent to some of a "coal tar" smell. The name "cresol" is an adduct of phenol and their traditional source, creosote.
The cumene process is an industrial process for synthesizing phenol and acetone from benzene and propylene. The term stems from cumene, the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR)., and independently by Heinrich Hock in 1944
1-Hexanol (IUPAC name hexan-1-ol) is an organic alcohol with a six-carbon chain and a condensed structural formula of CH3(CH2)5OH. This colorless liquid is slightly soluble in water, but miscible with diethyl ether and ethanol. Two additional straight chain isomers of 1-hexanol, 2-hexanol and 3-hexanol, exist, both of which differing by the location of the hydroxyl group. Many isomeric alcohols have the formula C6H13OH. It is used in the perfume industry.
In organic chemistry, dihydroxybenzenes (benzenediols) are organic compounds in which two hydroxyl groups are substituted onto a benzene ring. These aromatic compounds are classed as phenols. There are three structural isomers: 1,2-dihydroxybenzene is commonly known as catechol, 1,3-dihydroxybenzene is commonly known as resorcinol, and 1,4-dihydroxybenzene is commonly known as hydroquinone.
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 and is an isomer of o-cresol and m-cresol.
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.
2,4-Dimethyl-6-tert-butylphenol is the organic compound with the formula Me2(tert-Bu)C6H2OH (Me = methyl, tert-Bu = tertiary butyl). It is a colorless oil that is classified as an alkylated phenol.
2,6-Di-tert-butylphenol is an organic compound with the structural formula 2,6-((CH3)3C)2C6H3OH. This colorless solid alkylated phenol and its derivatives are used industrially as UV stabilizers and antioxidants for hydrocarbon-based products ranging from petrochemicals to plastics. Illustrative of its usefulness, it prevents gumming in aviation fuels.
2,6-Xylidine is an organic compound with the formula C6H3(CH3)2NH2. It is one of several isomeric xylidines. It is a colorless viscous liquid. Commercially significant derivatives are the anesthetics lidocaine, bupivacaine, mepivacaine, and etidocaine.
Durene, or 1,2,4,5-tetramethylbenzene, is an organic compound with the formula C6H2(CH3)4. It is a colourless solid with a sweet odor. The compound is classified as an alkylbenzene. It is one of three isomers of tetramethylbenzene, the other two being prehnitene (1,2,3,4-tetramethylbenzene) and isodurene (1,2,3,5-tetramethylbenzene). Durene has an unusually high melting point (79.2 °C), reflecting its high molecular symmetry.
2-Naphthol, or β-naphthol, is a fluorescent colorless (or occasionally yellow) crystalline solid with the formula C10H7OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, but more reactive. Both isomers are soluble in simple alcohols, ethers, and chloroform. 2-Naphthol is a widely used intermediate for the production of dyes and other compounds.
Alkylphenols are a family of organic compounds obtained by the alkylation of phenols. The term is usually reserved for commercially important propylphenol, butylphenol, amylphenol, heptylphenol, octylphenol, nonylphenol, dodecylphenol and related "long chain alkylphenols" (LCAPs). Methylphenols and ethylphenols are also alkylphenols, but they are more commonly referred to by their specific names, cresols and xylenols.
p-Chlorocresol is an organic compound with the formula ClC6H3CH3OH. Classified as a monochlorinated m-cresol, it is a white or colorless solid that is only slightly soluble in water. As a solution in alcohol and in combination with other phenols, it is used as an antiseptic and preservative.
ortho-Cresol, also called 2-methylphenol, or 2-hydroxytoluene, 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.
4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is a pale yellow solid. It is one of three isomers of nitrotoluene.
Mesitol (2,4,6-trimethylphenol) is an organic compound with the formula (CH3)3C6H2OH. It is one of several isomers of trimethylphenol. The name and structure of mesitol derives from the combination of mesitylene and phenol.
2-Ethylphenol is an organic compound with the formula C2H5C6H4OH. It is one of three isomeric ethylphenols. A colorless liquid, it occurs as an impurity in xylenols and as such is used in the production of commercial phenolic resins. It is produced by ethylation of phenol using ethylene or ethanol in the presence of aluminium phenolate.
2,3,6-Trimethylphenol is an organic compound with the formula (CH3)3C6H2OH. As a precursor to vitamin E, it is the most widely used of the several isomers of trimethylphenol.
4-Isopropylphenol is an organic compound with the formula (CH3)2CHC6H4OH. The molecule consists of an isopropyl group affixed to the para (p-) position of phenol. The compound, a white solid, is produced by the alkylation of phenol with propylene and is relevant to the production of the commodity chemical bisphenol A (BPA). The preparation of isopropylphenols by alkylation of phenol and various cresols with propylene has been well developed. Depending on the catalysts and conditions, products can include, aside from 4-isopropylphenol, 2-isopropylphenol, 2,6-diisopropylphenol, and 2,4,6-2-triisopropylphenol.