581-40-8

Usage

Uses

Used in Chemical Industry:
2,3-DIMETHYLNAPHTHALENE is used as a chemical compound for the identification of individual aromatic hydrocarbons in the kerosene fraction with a boiling point range of 150-250°. Its unique chemical structure allows for the differentiation and analysis of various aromatic hydrocarbons within this specific boiling point range, which is crucial for the chemical industry in understanding and managing the composition of kerosene and related products.
Used in Analytical Chemistry:
In the field of analytical chemistry, 2,3-DIMETHYLNAPHTHALENE serves as a reference compound for the detection and quantification of aromatic hydrocarbons. Its distinct properties make it an ideal candidate for calibration and standardization processes in various analytical techniques, such as gas chromatography and mass spectrometry, which are essential for accurate and reliable measurements in research and quality control.
Used in Environmental Monitoring:
2,3-DIMETHYLNAPHTHALENE is also utilized in environmental monitoring and assessment, particularly in the detection and analysis of pollutants in air, water, and soil samples. Its unique chemical properties enable the identification and quantification of specific aromatic hydrocarbons, which can be indicative of various environmental issues, such as contamination from industrial activities or the presence of hazardous substances.
Used in Research and Development:
In the realm of research and development, 2,3-DIMETHYLNAPHTHALENE plays a significant role as a model compound for studying the properties and behavior of aromatic hydrocarbons. Its use in various experimental setups helps scientists and researchers gain a deeper understanding of the chemical interactions, reactions, and transformations involving these types of compounds, which can lead to the development of new materials, processes, and technologies.

Purification Methods

Steam distil the naphthalene and crystallise it from EtOH. [Beilstein 5 IV 1713.]

InChI:InChI=1/C12H12/c1-9-7-11-5-3-4-6-12(11)8-10(9)2/h3-8H,1-2H3

Upstream product

• 1076-61-5 6,7-dimethyltetralin 
• 21564-83-0 2,3-dimethyl-1,2-dihydronaphthalene 
• 100519-05-9 2,3-Dimethylnaphthalin-1-sulfonsaeure 
• 6262-45-9 1,2-dichloro-3,3-difluorocyclopropene 
• 65957-27-9 2,3-bis(methylene)-1,2,3,4-tetrahydronaphthalene 
• 21564-72-7 1,4-Dihydro-2,3-dimethylnaphthalene 
• 75376-99-7 Trimethyl-(3-methyl-naphthalen-2-ylmethyl)-ammonium; iodide 
• 78239-39-1 cis-N,N,N',N'-tetramethyl-1,2,3,4-tetrahydronaphthalene-2,3-bis(methylamine) N,N'-dioxide 
• 34599-61-6 2,3-dimethyl-1-keto-1,2,3,4-tetrahydronaphthalene 
• 75-26-3 isopropyl bromide 
• 67-56-1 methanol 
• 91-57-6 2-Methylnaphthalene 
• 7193-16-0 1,3-dihydronaphtho<2,3-c>furan 
• 71-43-2 benzene 

Downstream Products

• 131543-46-9 Glyoxal 
• 431-03-8 dimethylglyoxal 
• 78-98-8 2-oxopropanal 
• 85-44-9 phthalic anhydride 
• 5334-79-2 1-bromo-2,3-dimethylnaphthalene 
• 38998-33-3 2,3-di(bromomethyl)naphthalene 
• 24055-46-7 1-Nitro-2.3-dimethyl-naphthalin 
• 2169-87-1 naphthalene-2,3-dicarboxylic acid 
• 1076-61-5 6,7-dimethyltetralin 
• 39171-57-8 2-Bromomethyl-3-methylnaphthalene 
• 19930-62-2 1,4-dibromo-2,3-dimethylnaphthalene 
• 71383-01-2 bis(dibromomethyl)-2,3 naphtalene 
• 6271-14-3 (2,3-dimethylnaphthalen-1-yl)(phenyl)methanone 
• 855933-86-7 1-(6,7-dimethyl-[2]naphthyl)-2-phenyl-ethanone 

Relevant academic research and scientific papers

Synthesis of Nanosized ZSM-5 Zeolites by Different Methods and Their Catalytic Performance in the Alkylation of Naphthalene

Abstract: Three nanosized ZSM-5 zeolites were successfully prepared from reactive gelswith the same Si/Al ratios by different synthetic procedures that included theuse of tetrapropylammonium hydroxide or n-butylamine as a template and a seedingmethod that did not use an organic additive. The effect of the synthetic methodon the physicochemical properties of the prepared samples was investigated byXRD, XRF, XPS, N2 physisorption, SEM, TEM,27Al MAS NMR, NH3-TPD, andPy-FTIR. The catalytic performance of thenanosized ZSM-5 zeolites in the alkylation of naphthalene with methanol wascompared. The prepared samples were phase-pure, highly crystalline ZSM-5zeolites, but they had different bulk and surface Si/Al ratios as well astextural and acidic properties. The study of the prepared catalysts innaphthalene methylation revealed that both the acid characteristics of the ZSM-5nanosized zeolites and their textural properties were responsible for theiractivity in the reaction. A difference in the composition ofmonomethylnaphthalenes and dimethylnaphthalenes was attributed to the ability ofthe catalyst to isomerize the primary reaction products on acid sites located onthe external surface of the zeolite crystals. 2,7-DMN was found to be thepreferred reaction product over 2,6-DMN when formed at pore entrances to ZSM-5channels due to the differences in their dimensions. In contrast,2,6-dimethylnaphthalene could be produced on weaker external Br?nsted acidsites, which are hydroxyls attached to octahedral Al atoms. The presentedresults show that the method used to synthesize nanoscale ZSM-5 zeolites is acritical factor that determines the physicochemical properties and catalyticperformance of the resulting crystals.

Selective synthesis of 2,6-triad dimethylnaphthalene isomers by disproportionation of 2-methylnaphthalene over mesoporous MCM-41

2,6-Dimethylnaphthalene (2,6-DMN) is one of the crucial intermediates for the synthesis of polybutylenenaphthalate and polyethylene naphthalate (PEN). The complex synthesis procedure and the high cost of 2,6-DMN production significantly reduce the commercialisation of PEN even though PEN demonstrates superior properties compared with polyethylene terephthalate. 2,6-DMN can be produced by methylation of 2-methylnaphthalene (2-MN) and/or naphthalene, disproportionation of 2-MN, and/or isomerisation of dimethylnaphthalenes (DMNs). In this study, synthesis of 2,6-triad DMN isomers consisting of 2,6-DMN, 1,6-DMN, and 1,5-DMN have been investigated with the disproportionation of 2-MN over unmodified and Zr-modified mesoporous MCM-41 zeolite catalysts. In contrast to other DMN isomers, both 1,5-DMN and 1,6-DMN can be effectively isomerised to be profitable 2,6-DMN. The disproportionation of 2-MN experiments were carried out in a catalytic fixed-bed reactor in the presence of 1?g of catalyst at a temperature range of 350–500?°C and weight hourly space velocity between 1 to 3?h?1. The results demonstrated that mesoporous MCM-41 zeolite catalyst has a selective pore shape for 2,6-triad DMN isomers, which may allow a decrease in the production cost of 2,6-DMN. Additionally, 2,6-DMN was successfully synthesised by the disproportionation of 2-MN over MCM-41 zeolite catalyst. Furthermore, both the conversion of 2-MN and the selectivity of 2,6-DMN were considerably enhanced by the Zr impregnation on MCM-41.

Benzannulation via ruthenium-catalyzed diol-diene [4+2] cycloaddition: One- and two-directional syntheses of fluoranthenes and acenes

A new benzannulation protocol is described and applied to the synthesis of polycyclic aromatic hydrocarbons. Ruthenium(0)-catalyzed diol-diene [4+2] cycloaddition delivers cyclohex-1-ene-4,5-diols, which are subject to aromatization upon dehydration or Nicholas diol deoxydehydration. Employing diol and tetraol reactants, benzannulation can be conducted efficiently in one- and two-directional modes, respectively, as illustrated in the construction of substituted fluoranthenes and acenes.

Methylation of naphthalene on MTW-type zeolites. Influence of template origin and substitution of Al by Ga

Two templates, methyltriethylammonium bromide (MTEA) and tetraethylammonium bromide (TEA) were used to synthesize aluminosilicate ZSM-12 zeolites. Additionally, zeolites isomorphously substituted (partially or totally) by gallium were prepared with MTEA.

Gold-catalyzed [4+3]-annulation of oxabicyclic benzenes with 2-substituted allylsilanes through tandem allylation and cyclization

This work reports new gold-catalyzed [4 + 3]-annulations of oxacyclic benzenes with 2-substituted allylsilanes through tandem allylation and cyclization; on the basis of experimental observations, we propose a mechanism involving the opening of the oxacyclic ring by a PPh3Au +assisted SN2-attack of allylsilanes.

Selective methylation catalyst, method of catalyst manufacture and methylation process

Novel catalysts and processes in accordance with the invention can accomplish high selectivity and conversion of naphthalenic compounds such as the conversion of methylnaphthalene (2-MN) or naphthalene to 2,6-dimethylnaphthalene (2,6-DMN). The catalysts are prepared by treating, for example, a ZSM-5-type material with iron in the presence of a halogen such as a fluoride. The resulting catalyst includes iron, as well as a significant portion of aluminum present in the ZSM-5-type starting material. Processes for using the catalysts also are disclosed.

Semivolatile and volatile compounds in combustion of polyethylene

The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.

Further studies of the thermal and photochemical Diels-Alder reactions of N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) with naphthalene and some substituted naphthalenes

MeTAD thermally reacted with naphthalene (2) and methylated naphthalenes to give equilibrium mixtures of starting materials and [4 + 2] cycloadducts. Methyl substitution on the naphthalene ring generally increased both the amount of cycloadduct formed and the rate of cycloaddition relative to 2. The isolated cycloadducts were all thermally labile and quantitatively reverted to the parent naphthalene in the presence of 2,3-dimethyl-2-butene as a trap for liberated MeTAD. The rates of the cycloreversion reactions were affected by substitution patterns but not appreciably by solvent. A mechanism for the cycloaddition reaction is presented that proposes the involvement of a charge-transfer complex. Photochemically, MeTAD demonstrated lower regioselectivity in its reactions with substituted naphthalenes relative to the corresponding thermal reactions.

Electron-transfer-induced reductive cleavage of phthalans: Reactivity and synthetic applications

The behavior of phthalan (1a) was investigated under conditions of electron transfer from alkali metals in aprotic solvents. Reaction with lithium in the presence of a catalytic amount of naphthalene in THF led to the reductive cleavage of an arylmethyl carbon-oxygen bond, with formation of a stable dilithium compound. Trapping of this intermediate with several electrophiles (alkyl halides, carbonyl derivatives, CO2) was successful. The extension of this procedure to several substituted phthalans (1b-i) was investigated, and the regiochemistry as well as the synthetic usefulness of these reactions are discussed.