2,6-Dimethylnaphthalene

2,6-dimethylnaphthalene.svg 200px 2,6-Dimethylnaphthalene 581-42-0 correct CAS 76U29QW3FM correct FDA 11387 10909 34251 Cc1ccc2cc(ccc2c1)C 1/C12H12/c1-9-3-5-12-8-10(2)4-6-11(12)7-9/h3-8H,1-2H3 YGYNBBAUIYTWBF-UHFFFAOYAZ 1S/C12H12/c1-9-3-5-12-8-10(2)4-6-11(12)7-9/h3-8H,1-2H3 YGYNBBAUIYTWBF-UHFFFAOYSA-N 12 12 white solid 110 261 101.3 kPa 2,6-Dimethylnaphthalene (2,6-DMN) is a polycyclic aromatic hydrocarbon with the formula C10H6(CH3)2. It is one of the ten isomers of dimethylnaphthalenes.10.1002/14356007.a17_001.pub2 Naphthalene and Hydronaphthalenes 2003 Collin Gerd Höke Hartmut Greim Helmut Synthesis Alkylated naphthalenes (methyl-, dimethyl-, and poly-methyl naphthalenes, thus including 2,6-DMN) are found in crude oil and coal tar. Separation is difficult, expensive, and requires a number of operations such as selective crystallization and adsorption, in addition to any isomerization reactions. Alternative routes to 2,6-DMN remains of interest. 5004853 April 2, 1991 Paul T. Barger, Timothy J. Barder, David Y. Lin, Simon H. Hobbs Continuous process for the production of 2,6-dimethylnaphthalene In the "alkenylation process" butadiene (1), o-xylene (2), and sodium–potassium alloy (3) are used, which react to form 5-(ortho-tolyl)pent-2-ene (OTP, 3). March 30, 1993 Lawrence D. Lillwitz, Anne M. Karachewski Alkylation of alkylaromatics promoted by sonicated alkali metal OTP is subsequently cyclized to 1,5-dimethyltetraline (4). Dehydrogenation then provides 1,5-dimethylnaphthalene (1,5-DMN, 5). Finally, 1,5-DMN is isomerized to 2,6-DMN (6). In the final step, other mono-, di-, and tri-methylnaphthalenes are formed. More work is therefore required in separation of the mixture, which is done by selective crystallization. thumb|left|600px|Synthesis of 2,6-dimethylnaphthalene by the alkenylation process Applications 2,6-Dimethylnaphthalene is mainly used for the preparation of 2,6-naphthalenedicarboxylic acid by oxidation of 2,6-dimethylnaphthalene in the liquid phase. 2,6-Naphthalenedicarboxylic acid is a monomer for the production of high-performance polymers, in particular poly (ethylene-2,6-naphthalene dicarboxylate) or shorter polyethylene naphthalate (PEN).10.1016/S0926-860X(01)00809-2 Production of Dimethyl-2,6-Naphthalenedicarboxylate: Precursor to Polyethylene Naphthalate Lillwitz L. D. Applied Catalysis A: General 2001 221 1–2 337–358 That polyester is stronger and has a higher thermal resistance than the more frequently used polyethylene terephthalate (PET). 2,6-Dimethylnaphthalene undergoes ammoxidation to give the 2,6-dicyanonaphthalene, which can be hydrogenated to bis(aminomethyl)naphthalene, a precursor to dyes.10.1002/14356007.a17_363 Nitriles 2000 Pollak Peter Romeder Gérard Hagedorn Ferdinand Gelbke Heinz-Peter 3527306730 References Category:Aromatic hydrocarbons Category:Naphthalenes