2-Methyl-naphthalene Compound

Potassium-catalyzed ethylation of alkylnaphthalenes proceeds at 90-160° and, besides the normal side-chain ethylation, a cyclialkylation also occurs. From 1-methyl-naphthalene compounds and 20 are obtained, and from 2-methylnaphthalene compound 2fTs obtained. 

Mel ancon and Lech (9) demonstrated that rainbow trout exposed to both radiolabeled naphthalene and 2-methyl naphthalene contained significant portions of polar compounds (unspecified) after about four weeks of exposure (Table IV). Mai ins et al. (15J showed that a variety of metabolic products accumulate in tissues and... 

The growth step procedures for the cycloaddition reaction are very simple. Combination of an ethynyl-substituted dendrimer and an excess of the cyclo-pentadienone in a refluxing solvent such as o-xylene, diphenylether, or methyl-naphthalene (with b.p. higher than 130 °C) typically results in quantitative conversion within 24 h. The refluxing of the solvent is necessary to accelerate the elimination of the carbon monoxide in the cycloaddition. The purity of the resulting compounds was checked by MALDI-TOF mass spectrometry which showed quantitative reaction, facilitating work-up. By repeated precipitation in methanol, the pure product can be isolated as white amorphous powders in yields higher than 90%. 

Figure 2. Absorption spectra of compounds 2(a) and 10(b) in EPIP and 6(c) in THF-DE. 1 - 500 K (in methyl naphthalene), 2 - 293 K, 3 - 77 K.. (Reproduced with permission from Ref. 12. Copyright 1984 North-Holi and Physics Publishing Company.)...

The decrease in oxidation potential of 1,3,14,16-tetramethylhexahelicene (1.13 and 1.32 V) compared to hexahelicene ( 1/2 = 1.29, no 2nd wave below 2 V) is small in comparison with that of naphthalene compared to its methyl derivatives. Therefore, it was concluded that the increased oxidizability of the methyl-substituted compounds is mainly due to the electronic effect of the methyl groups and not to conformational differences. 

A systematic study of the run-to-run reproducibility for the analysis of a mixture of neutral molecules consisting of thiourea, benzyl alcohol, benzaldehyde, and 2-methyl-naphthalene was carried out over a period of 3 days. Figure 6.36 shows electrochromatograms of runs 10, 30, and 50. There is almost no variation in retention times of all test compounds. The relative standard deviations for retention factor, the efficiency, and the resolution, averaged over 60 runs, are 3.5%, 3.3%, and 5.5%, respectively. The integrity of the packed column remained unchanged, and the column... 

The importance of steric strain arising from benzo fusion in pyridines was first estimated by Packer and Wong (58JA905) in quaternization of methyl-substituted quinolines and isoquinolines. They used the strained homo-morph concept of Brown (53JA1) to approximate strains existing in naphthalene compounds of similar geometry (e.g., 1-methylquinoline and 1-methylnaphthalene) (Scheme 8). 

All possible interactions between the K and L groups were taken into account and Akk = 0. The definition contains a minimum number of groups and is satisfactory for most of the binary systems studied. However, it cannot take into account the structural differences which exist between position isomers. This is the case of polycyclic aromatic compounds presenting cycle position isomers or substitute position isomers. Structural differences of this type determine the gaps between the values of certain thermophysical properties of isomers, such as, for example, the fusion temperature or sublimation enthalpy. The further the temperature falls, the more these differences are accentuated. The representation of the solid-fluid (low temperature) equilibria is consequently more difficult and the model must take into account the existing structural differences. We came across this problem in the compounds such as anthracene, phenanthrene, pyrene, methylated naphthalenes, hexamethylbenzene and triphenylmethane. As it was out of the question to increase the number of groups because... 

Apart from the metal atom aggregation reactions described below, bis(arene)metal complexes of the early transition metals are resistant to ligand displacement The rings on the corresponding bis(naphthalene)metal species (41) are by, contrast, labile. Polymer-supported analogs of these naphthalene compounds with vanadium and chromium are known (42), but Ti atoms attack the polymer at the silicon ether linkage. These and other hybrid polymers can be further modified once the metal atom is incorporated. Thus a-methyl naphthalene is displaced from the hybrid organometallic polymer shown in Scheme 7 (43). 

Predict the most favourable sites of mononilration for the following compounds and give reasons for your choice (a) naph-lhalene-2-carboxylic acid (b) 2-melhylnaphthalene (c) 1-methyl-naphthalene (d) ]-naphthol (e) 2-naphthol (f) l-nitronaphlhaleiie. 

C values to be expected from potential precursors (e.g., triterpenoids) remains to be fully defined. O Malley (1994) reported depletion in (up to 2%c) methylated naphthalene homologues compared to their corresponding parental compound. The fi C-depleted isotopic values observed in these petrogenic-associated PAHs may be dictated by Ae similarly depleted nature of the precursor compounds. Published 6 C values of petrogenic-associated PAHs are limited, and it is more than likely that further analysis will reveal more variations that would reflect the isotopic composition of precursor compounds and the nature and degree of diage-netic reactions. 

Some kinds of proton sponges are best prepared starting from accessible l,8-bis(methyl-amino)naphthalene (4) or its derivatives2,40-43. For example, the optimal synthesis of l,8-bis(dimethylamino)-4,5-dinitronaphthalene (51) consists in methylation of compound 50, which in turn can be prepared from perimidone 49 (Scheme 2)44,45. 

Oral Exposure. The only MRLs available for this fraction are acute and subchronic MRLs for naphthalene, an intermediate MRL for acenaphthene, and a chronic MRL for 1-methyl naphthalene these MRLs are listed in Table 6-6. Although more health effects data are available for oral exposure than for inhalation exposure to the constituents of this fraction, selection of surrogate values to use for oral exposure to this fraction is problematic. The acute and intermediate MRLs for naphthalene, 0.05 and 0.02 mg/kg/day, are equivalent to or lower than any other MRLs for this fraction, including the chronic MRL for 1-methyl naphthalene. The compounds in this fraction tend to cause hepatic and renal effects. Naphthalene and 1-methyl naphthalene have respiratory effects following oral exposure it is expected that... 

The alkyl naphthalenes, such as methyl naphthalene, may be oxidized to phthalic anhydride in the same manner as naphthalene, thus making it possible to use cruder grades of naphthalene. Thus, crude naphthalene obtained by centrifuging the oils from the proper cut from the distillation of coal-tar (whizzed naphthalene) consisting principally of naphthalene to the extent of 50 to 80 per cent and usually containing considerable quantities of alkyl naphthalenes and other ring compounds may be treated in a manner similar to that used in the oxidation of pure naphthalene. The reaction products contain phthalic anhydride, benzoic acid, naphthoic acids and anhydrides, etc.81... 

A second study characterizing a huge groundwater contamination caused by chemicals used for wood impregnation revealed mono- and dichlorinated naphthalenes, chlorobenzo(b)thiophene, acenaphthene and methylated naphthalenes as the main pollutants. Anaerobic microbial degradation of the main pollutant 1-chloronaphthalene was evident from identification of 1 -chloro-4-naphthol and 1-chloronaphthoic acid as biotic transformation products. In contrast inorganic and compound specific stable carbon isotope analyses indicated only a minor degree of microbial transformation. Thus, sorption seemed to be the main attenuation process within the aquifer affected by the coal tar based contamination described above. 

To the starting thiocyanate (0.01 mol), dissolved in a sufficient amount of acetone (usually 50 mL) was added aniline (1.2 g, 13 mol). After evaporation of the solution at rt (Caution evolution of HCN ), the dry residue was recrystallized (petroleum ether or cyclohexane). For the naphthalene compound, short warming in EtOH was used. The reactions with methyl anthranilate were performed by refluxing for 5 min in acetone. 

Naphthalenic compounds such as 4,8-dimethoxy-6-methyl-1-naphthol can be oxidatively coupled essentially by way of a cyclohexadienone. The naphthol... 

The so-called antiplasticizers are used in PET bottle manufacturing to enhance the gas barrier. The proposed additives comprise aromatic hydroxy and carboxylic group containing benzene and naphthalene compounds, for example, methyl-4-hydroxybenzoate or... 

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