Disubstituted Naphthalenes Research Articles

ChemInform Abstract: Neighboring Rotor Substituents on Arene Systems. Part 2. 1,8‐ Disubstituted Naphthalenes by Directed Metalation and Subsequent Lithium‐Manganese Exchange, Including Copper Catalysis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Generation and fragmentation of didehydronaphthalene radical cations under electron impact

AbstractThe electron impact mass spectra of disubstituted naphthalenes (chloronitro, acetylnitro, dibromo and dinitro derivatives) and of two naphthalenedicarboxylic anhydrides were studied under high resolution and by means of linked (B/E) scans. They all generate didehydronaphthalene radical cation, C10H, in most cases with a very high abundance, so that a convenient route to these interesting species is provided. These isomeric ions were all seen to lose the same fragments, namely C2H2, C2H4, C3H3, C4H2, or C2H2 + C2H2. In three instances, mass‐analysed ion kinetic energy spectrometric (MIKES) and collisional activation/MIKES experiments were carried out and no differences in fragmentation behaviour were detected. Hence these isomeric C10H6+˙ ions achieve some common structure either before or during the fragmentation.

ChemInform Abstract: Stereoselective Synthesis of Disubstituted Naphthalene 1,2‐Oxides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Ionic hydrogenation of disubstituted naphthalenes with boron fluoride hydrate (BF3.H2O) triethylsilane

A number of dimethoxy-substituted naphthalenes and their mono N(CH 3 ) 2 or SCH 3 analogues are reduced by using Et 3 SiH or Et 3 SiD in boron trifluoride monohydrate. Reaction mechanisms are discussed on the basic of ionic deuteration experiments. The mode of protonation of the starting compounds is rationalized in terms of proton affinities calculated by using MNDO procedure

Patent Evaluation: Disubstituted naphthalenes and quinolines as leukotriene antagonists

Patent Evaluation: Disubstituted naphthalenes and quinolines as leukotriene antagonists

The application of C8K for organic synthesis: reduction of substituted naphthalenes

The reduction of disubstituted naphthalene derivatives by potassium–graphite intercalate C8K is reported. The reduction is carried out at 0 °C in tetrahydrofuran. The C8K–ether system suggests an alternative route for the Birch type reaction and the mechanism is discussed vis-a-vis the reaction in liquid ammonia.

Substitution effect on the triplet state energy and decay of some disubstituted naphthalenes

Singlet- and triplet-state energy positions and triplet-state decay lifetimes of some 2,6- and 2,7-distributed naphthalene molecules, in which the substituents are OCH 3, -CN; -OCH 3, -CO 2CH 3; and -OCH 3, -COOH, have been determined in ethanol glass at 77 K. It has been found that the first excited singlet-state energy, the triplet-state energy and the triplet-state decay lifetime of the two members in each of the systems show similar dependence on the relative positions of the substituents. All the three are lower in the 2,7-compound than in the 2,6-compound.

Synthesis and carbon-13 NMR study of some methanesulfonyloxy and trifluoroacetoxy derivatives of naphthalene

Several mono- and di-methanesulfonyloxy (mesyloxy) and trifluoroacetoxy derivatives of naphthalene were prepared and their C-13 NMR recorded. The C-13 NMR spectra were analysed and the complete assignment of aromatic carbon chemical shifts reported. The substituent induced chemical shifts of naphthalene due to mesyloxy and trifluoroacetoxy groups were derived and compared with that of the hydroxy substituent. Carbon chemical shifts of disubstituted naphthalenes were calculated by simple additivity of substituent induced chemical shifts. The experimental chemical shifts were compared with the calculated shifts and deviations discussed in terms of steric and electronic effects of the substituents.

NMR study of some mono- and di- tert-butylnaphthalenes

The proton decoupled 13C FT—NMR spectra and 1H FT—NMR spectra of some mono- and di- tert-butylnaphthalenes have been studied. Some interesting features observed in these spectra have been found to be of diagnostic value in distinguishing the closely related isomers of these compounds. On the basis of the assignment done by earlier workers in case of mono-substituted naphthalenes following the additivity approach, it has been shown that all the 13C—NMR signals observed for the present di-substituted naphthalenes can also be assigned; and this procedure thus obviates the use of tedious and some times experimentally inaccessible techniques.

Flammability and thermal properties of rigid polyurethane foams with additionally introduced cyclic structures

Flammability, smoke evolution, thermal, and thermomechanical properties of low-density rigid polyurethane foams obtained from different aromatic polyols were investigated. The foams were prepared according to a standard formulation ensuring the same foam phosphorus content. Cellular polyurethanes with the best fire resistance were obtained from polyols containing disubstituted naphthalene and biphenyl rings. A linear equation was proposed to describe the influence of various structural units of the polyurethane (the content of cyclic structures Cc, nitrogen content CN, and crosslinking equivalent Mc) upon its flammability, expressed in terms of its oxygen index (OI) Thermal stability of crosslinked polyurethanes was not found to influence significantly their thermomechanical properties, while crosslink density and the type and quantity of cyclic structures additionally introduced did have a pronounced effect upon these properties.

Proton magnetic resonance spectra of some disubstituted naphthalenes

AbstractThe chemical shifts and coupling constants for the ring protons of nine disubstituted naphthalenes (mainly halogenonitre compounds) in carbon tetrachloride solutions have been obtained by analysis and computer simulation of their 100 MHz magnetic resonance spectra. Substituent effects are essentially additive except when a strong π‐donor group is in direct conjugation with a strong π‐acceptor group.

ChemInform Abstract: PHOTOCHEMICAL SYNTHESES. X. PHOTODIMERS OF DERIVATIVES OF NAPHTHALENECARBOXYLIC ACIDS

AbstractEine Reihe von Naphthalincarbonsäureestern bilden Photodimere, wie z.B. die Ester (I) und (IV) die Dimeren (II) und (V).

An Infra-red spectroscopic study of naphthalene substitution

Infra-red spectroscopic data on a number of mono- and disubstituted naphthalene derivatives have been obtained in the range 670-900 cm-l, in order to test the validity of the substitution rules based upon the hydrogen bending vibrations in this region and the number of adjacent hydrogen atoms in the molecules. It was found that the rules based on benzene substitution are generally valid for groups of two, three, or four hydrogen atoms in the naphthalene nucleus, although substituents which interact with the ring tend to widen the limits within which a band may be expected to fall. In the case of a single hydrogen atom the relevant bands are often weaker and their position variable.

THE BROMO-ALPHA-NAPHTHOLS AND THE ORIENTATION OF CERTAIN CLASSES OF DISUBSTITUTED NAPHTHALENE DERIVATIVES

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTHE BROMO-ALPHA-NAPHTHOLS AND THE ORIENTATION OF CERTAIN CLASSES OF DISUBSTITUTED NAPHTHALENE DERIVATIVESReynold C. FusonCite this: J. Am. Chem. Soc. 1925, 47, 2, 516–518Publication Date (Print):February 1, 1925Publication History Published online1 May 2002Published inissue 1 February 1925https://doi.org/10.1021/ja01679a035RIGHTS & PERMISSIONSArticle Views75Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (229 KB) Get e-Alerts Get e-Alerts