569-41-5Relevant articles and documents
Selective synthesis of 2,6-triad dimethylnaphthalene isomers by disproportionation of 2-methylnaphthalene over mesoporous MCM-41
Güle?, Fatih,Niftaliyeva, Aysel,Karaduman, Ali
, p. 7205 - 7218 (2018)
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.
Synthesis and properties of dicarboximide derivatives of perylene and azaperylene
Nagao, Yukinori,Yoshida, Tatsurou,Arimitsu, Koji,Kozawa, Kozo
experimental part, p. 1197 - 1213 (2010/10/04)
The N-alkyl dicarboximide derivatives of naphthylisoquinoline and binaphthalene were prepared by the hetero coupling reaction of the corresponding N-alkyl dicarboximide derivatives of stannylnaphthalene with bromodimethyisoquinoline and bromodimethylnaphthalene, respectively. The ring closing of the N-hexyl derivatives of naphthylisoquinoline and binaphthalene produced the N-hexyldicarboximide derivatives of azaperylene and perylene having the same substituents, respectively. The absorption spectra and fluorescence spectra of the azaperylene and perylene derivatives were investigated.
Photooxidation of methylnaphthalenes
Wasserman, Harry H.,Wiberg, Kenneth B.,Larsen, David L.,Parr, Jonathan
, p. 105 - 109 (2007/10/03)
(Chemical Equation Presented). Studies on the photooxidation of methyl-substituted aromatic hydrocarbons have revealed that whereas electron density is a determinant of endoperoxide formation, steric factors are most important in influencing the stability of the endoperoxide. Additional information on the energetics of the reactions and on the magnitude of the steric interactions was obtained using calculations at the B3LYP/6-311+G* level of theory.
Complete study of the pyrolysis and gasification of scrap tires in a pilot plant reactor
Conesa, Juan A.,Martin-Gullon,Font,Jauhiainen
, p. 3189 - 3194 (2008/12/21)
The pyrolysis and gasification of tires was investigated in a pilot plant reactor provided with a system for condensation of semivolatile matter. The study comprised experiments at 450°, 750°, and 1000°C both in nitrogen and 10% oxygen atmospheres. In the gas phase, only methane and benzene yields increased with temperature until 1000°C. In the liquids, the main components were styrene, limonene, and isoprene. The solid fraction (including soot) increased with temperature. Zinc content of the char decreased with increasing temperature. Analysis of the surface area of the solids showed that the area was similar in all cases to that of a commercial carbon black. The higher surface of the soot with respect to the chars was observed. The results coincided with published findings, i.e., kinetic severity function values would produce 0.2% of methane at 450°C and 4.5% at 750°-1000°C.
Photolytic, thermal, addition, and cycloaddition reactions of 2-diazo-5,6- and -3,8-disubstituted acenaphthenones
Blair, Patricia A.,Chang, Sou-Jen,Shechter, Harold
, p. 7123 - 7133 (2007/10/03)
Preparation and varied thermal and photolytic reactions of 2-diazo-5,6-(disubstituted)acenaphthenones (11a-d) and 2-diazo-3,8- dimethoxyacenaphthenone (12) are reported. Alcohols react thermally and photolytically with 11a-c with losses of N2 to yield 2-alkoxynaphthenones (24a,b and 47a,b) and acenaphthenones (25 and 48a,b). Aniline and diphenylamine are converted by 11a-c at 180°C to acenaph[1,2-6]indoles (29a,b and 53a,b). Thermolyses of 11a-c at ～450°C (0.15 mmHg) yield reduction products 25 and 48a,b, respectively. Wolff rearrangements to 1,8-naphthyleneketenes (15a-d) and/or their derivatives are not observed in the above experiments. Oxygen converts 11a-c thermally to acenaphthenequinones (19a-c) and/or 1,8-naphthalic anhydrides. Insertion, addition, substitution, and/or isomerization reactions occur upon irradiation of 2-diazoacenaphthenones in cyclohexane, benzene, and tetrahydrofuran. Photolysis of 11d in benzene in the presence of O2 yields the insertion-oxidation product 2-hydroxy-5,6-dinitro-2-phenylacenaphthenone (60). Photolyses of 11a-c in nitriles result in N2 evolution and dipolar cycloaddition to give acenaph[1,2-d]oxazoles (41 and 61a,b). Acetylenes undergo thermal and photolytic cycloaddition/1,5-sigmatropic rearrangement reactions with 11a-d with N2 retention to give pyrazolo[5,1-a]quinolin-7-ones (69f-j). 2-Diazoacenaphthenones 1a and 11a react thermally and photolytically with electronegatively-substituted olefins with N2 expulsion to yield (E)- and (Z)-2-oxospiro[acenaphthylene-1(2H),1′cyclopropanes] 73a-c and 74a-c, respectively. The mechanisms of the reactions of la, 11a-d, and 12 reported are discussed.
Reductive cleavage of benzannelated cyclic ethers and amines: Synthetic applications
Azzena, Ugo,Demartis, Salvatore,Pilo, Luciano,Piras, Elisabetta
, p. 8375 - 8382 (2007/10/03)
Reduction of symmetrical intramolecular diarylmethyl ethers (3a and 8a) and amines (3b and 8b) with alkali metals in THF allows the generation of unsymmetrical oxy- or amino-functionalised arylmethyl organometallics. Such intermediates were successfully trapped with various electrophiles, allowing a new access to unsymmetrically 2,2'-disubstituted-1,1'-biaryls (5aa-5bf) and 1,8-disubstituted naphthalenes (10aa-10be). (C) 2000 Elsevier Science Ltd.
New one-pot synthesis of a benzonorcaradiene derivative by reduction of naphthalic anhydride with LiAlH4
Wijsman, Geerlig W.,Van Der Veen, Lars A.,De Wolf, Willem H.,Bickelhaupt, Friedrich
, p. 2095 - 2098 (2007/10/03)
Reaction of naphthalic anhydride (naphthalene-1,8-dicarboxylic anhydride) (1) or of 1,8-bis(hydroxymethyl)naphthalene (3) with LiAlH4 in refluxing THF yields the benzonorcaradiene derivatives 2 in yields of up to 50%. It is proposed that in the formation of this (strained) product an anti-hydroalumination reaction is involved, which is facilitated by the assistance of a neighbouring alkoxide function.
Palladium-Catalyzed Methylation of Aryl and Vinyl Halides by Stabilized Methylaluminum and Methylgallium Complexes
Blum, Jochanan,Gelman, Dmitri,Baidossi, Wael,Shakh, Eduard,Rosenfeld, Ayelet,Aizenshtat, Zeev,Wassermann, Birgit C.,Frick, Michael,Heymer, Bernd,Schutte, Stefan,Wernik, Sonja,Schumann, Herbert
, p. 8681 - 8686 (2007/10/03)
The intramolecularly stabilized mono- and dialkylaluminum complexes 1a, 2, 3, 4a, 5a, 5c, 6a, 6c, 7, 8, and 9 in the presence of palladium catalysts, cross-alkylate aryl, vinyl, and benzyl bromides and iodides under mild standard laboratory conditions. Aryl bromides with carbonyl substituents or benzylic halides are converted partially into dialkyl compounds. Under similar conditions, the analogous stabilized dimethylgallium complexes 1b, 4b, 5b, 6b, and 10 methylate aryl and vinyl bromides and iodides in a highly selective manner. Substituted bromobenzenes XC6H4Br, where X = CHO, COPh, CO2Et, CN, NO2, Cl, CH2Br, or CH=CHCOPh, are methylated by the organogallium reagents usually only at the aromatic ring halogen atom to give substituted toluenes as single products. The methylation rates were shown to depend on the nature of the chelating ligands, on the solvent, and on the type of palladium catalyst employed.
Functionalization of the Methyl Group of 1,4-Dimethyl-1,4-dihydronaphthalene-1,4-endoperoxide
Jefford, Charles W.,Rossier, Jean-Claude,Kohmoto, Shigeo,Boukouvalas, John
, p. 1496 - 1497 (2007/10/02)
The acid-catalysed cleavage of 1,4-dimethyl-1,4-dihydronaphthalene-1,4-endoperoxide gives the 4-hydroxy, methoxy, trifluoroacetoxy, formyloxy, bromo, and chloro methyl derivatives of 1-methylnaphthalene in yields of 36, 38, 52, 76, 77, and 100percent respectively when water, methanol, trifluoroacetic, formic, hydrobromic, or hydrochloric acids are used as reagents.
