2,6-Xylenol

2,6-Xylenol is a chemical compound which is one of the six isomers of xylenol. It is also commonly known as 2,6-dimethylphenol (DMP).

2,6-Xylenol[1]
Names
Preferred IUPAC name
2,6-Dimethylphenol
Other names
2-Hydroxy-m-xylene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.547
UNII
Properties
C8H10O
Molar mass 122.167 g·mol−1
Melting point 43 to 45 °C (109 to 113 °F; 316 to 318 K)
Boiling point 203 °C (397 °F; 476 K)
Hazards
Flash point 86 °C (187 °F; 359 K)
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

A known application of DMP is in the synthesis of Mexiletine.

Production

2,6-DMP can be produced by the direct methylation of phenol. This is carried out with gaseous phenol and methanol at elevated temperatures in the presence of a catalyst[2]

2,6-Xylenol is a monomer for poly(p-phenylene oxide) engineering resins through carbon - oxygen oxidative coupling. Carbon-to-carbon dimerization is also possible. In one study 2,6-xylenol is oxidized with iodosobenzene diacetate with a fivefold excess of the phenol.[3]

In the first step of the proposed reaction mechanism the acetyl groups in the iodine compound are replaced with the phenol. This complex dissociates into an aryl radical anion and a phenoxy residue. The two aryl radicals recombine forming a new carbon-carbon covalent bond and subsequently lose two protons in a rearomatization step. The immediate reaction product is a diphenoquinone as result of a one-step 4-electron oxidation. It is nevertheless possible to synthesize the biphenol compound via a comproportionation of the quinone with xylenol already present. In this reaction sequence the hypervalent iodine reagent is eventually reduced to phenyliodine.

References
  1. 2,6-Xylenol at Sigma-Aldrich
  2. Zukowski, W.; Berkowicz, G.; Baron, J.; Kandefer, S.; Jamanek, D.; Szarlik, S.; Wielgosz, Z.; Zielecka, M. (2014). "Selective phenol methylation to 2,6-dimethylphenol in a fluidized bed of iron-chromium mixed oxide catalyst with o-cresol circulation" (PDF). Chemistry Central Journal. 8 (1): 51. doi:10.1186/s13065-014-0051-6. PMC 4172955. PMID 25342964.
  3. Selective oxidative para C–C dimerization of 2,6-dimethylphenol Christophe Boldron, Guillem Aromí, Ger Challa, Patrick Gamez and Jan Reedijk Chemical Communications, 2005, (46), 5808 - 5810 Abstract
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.