Homologues, naphthalene

Coal Tar.—These soaps contain, in addition to carbolic acid and its homologues, naphthalene and other hydrocarbons derived from coal, naphthol, bases, etc. Various blends of different fractions of coal tar are used, but the most valuable constituents from a disinfectant point of view are undoubtedly the phenols, or tar acids, though in this case as with carbolic and cresylic soaps, the amount of phenols should not exceed 3 per cent, in a toilet soap. An excess of naphthalene should also be avoided, since, on account of its strong odour, soaps containing much of it are unpopular. The odour of coal tar is considerably modified by and blends well with a perfum> containing oils of cassia, lavender, spike, and red thyme. 

Acetoxylation and nitration. It has already been mentioned that 0- and m-xylene are acetoxylated as well as nitrated by solutions of acetyl nitrate in acetic anhydride. This occurs with some other homologues of benzene, and with methyl phenethyl ether,ii but not with anisole, mesitylene or naphthalene. Results are given in table 5.4. 

The most abundant aromatics ia the mid-distiUate are mono-, di-, and trimethyl naphthalenes. Other one- and two-ting aromatics are undoubtedly present ia smaU quantities as either naphtheno or alkyl homologues ia the addition to these homologues of alkylben2enes, tetralins, and... 

Sodium naphthenide (naphthalene sodium) and Li or K homologues Sodium biphenyl [Alkali metal ketyis]... 

Krishnamurthy, T., Wasik, S.P. (1978) Fluorometric determination of partition coefficient of naphthalene homologues in octanol-water mixtures. J. Environ. Sci. Health A13(8), 595-602. 

UNIDAK A process for extracting naphthalene from reformer residues in petroleum refining. It includes a dealkylation stage to convert the naphthalene homologues to naphthalene. 

Cation-radicals of naphthalene and its homologues, pyrene, or perylene react with NOj" ion in AN, giving electron-transfer products, that is, ArH and NOj. The latter radical is not very active in these reactions and nitration takes place only with extremely reactive compounds such as perylene (Eberson and Radner 1985, 1986). This mechanism is seemingly distinctive of compounds with E° less or equal to 1 V in AN (or in other solvents solvating NOj ions sparingly). 

Aromatization of dihalocarbene adducts to 1,4-cyclohexadiene or synthetic equivalents is the method of choice for the synthesis of the parent benzocyclo-propene (1). ° The mechanism of the aromatization step of the intermediate 7,7-dihalogenobicyclo[4.1.0]hept-2-ene (51) has been shown by labeling experiments with 51 depleted of C at Cl, to proceed via a series of elimination and double bond migration steps via cyclopropene- and alkylidenecyclopropane intermediates 52 to 54 with preservation of the original carbon skeleton. The synthesis of the benzannelated homologue, l//-cyclopropa[b]naphthalene (42), by the same route confirms these findings. Some skeletal rearrangement has, however, been observed in an isolated case. ... 

The systematic nomenclature for the cycloproparenes is confused because the fusion rule (IUPAC Rule A 21.3) requires that at least two rings of five or more members be present before the prefix cyclopropa may be used. Thus while l//-cyclopropa[a]- and -[/ naphthalene are correct for 10 and 11, respectively, 1 //-cyclopropabenzene is incorrect for 1. The Chemical Abstracts service and IUPAC are unanimous in naming 1 as bicyclo-[4.1. Ojhepta-1,3,5-triene la. Thus if the parent member is strictly named, not only does it differ from that of its higher homologues, but also it could be taken to imply a bond localized structure. Throughout this chapter parent 1 and its derivatives 5-9 are referred to as cyclopropabenzenes and numbered as shown for structure 1. 

For selective epoxidation Rebek and coworkers synthesized highly crowded peroxyacids (1) and their naphthalene and acridine homologues and compared their epoxidation rates27. 

The most abundant aromatics in the mid-distillate fractions are di- and trimethyl naphthalenes. Other one and two ring aromatics are undoubtedly present in small quantities as either naphtheno- or alkyl-homologues in the Cn-C2orange. In addition to these homologues of alkylbenzenes, tetralin, and naphthalene, the mid-distillate contains some fluorene derivatives and phenanthrene derivatives. The phenanthrene structure appears to be favored over that of anthracene structure (Tissot and Welte, 1978 Speight, 1999). 

Figure 4 Example of the application of chrom-NMR/HRMAS with regular NMR solvents and bare silica as a solid phase. Left panel aromatic molecule homologues in deuterated chloroform benzene, naphthalene and anthracene. Right panel alcohol mixture ethylene glycol, phenol, isopropanol in deuterated water. Adapted with permission from Ref. 53. Copyright 2008 Elsevier.

Thus, oxidation reactions occurring along with a nitration reaction are particularly strong, whenever the aromatic ring is liable to such a reaction (e.g. oxidation of phenol to oxalic acid, oxidation of methyl groups in benzene homologues to hydroxymethyl and carboxyl group, oxidation of naphthalene to phthalic acid etc.). 

UNIDAK A process for extracting naphthalene from reformer residues in petroleum refining. It includes a dealkylation stage to convert the naphthalene homologues to naphthalene. The process temperature is approximately 600°C the catalyst is based on cobalt/molybdenum. Developed by the Union Oil Company of California. 

Ketone 8 and the naphthalene homologue can be generated in solution " from singlet oxygen addition to various alkylidenecycloproparenes (Section VLB.2). However, attempts to construct 87 from 5,7-dibromodibenzo[ ,c]cycloheptadienone were unsuccessful " and the only known condensed analogue is 88 that has been matrix isolated prior to photodecarbonylation". ... 

Except for 1 -monoCN, which is a liquid at room temperature, the chlorinated naphthalenes are crystalline compounds. The melting point increases with increasing chlorine substitution with considerable variation within each homolo-gue group, cf. Table 2. The commercial PCN products, which occur as complex mixtures of isomers and homologues, are generally waxes with high compatibility with other materials. The solid products melt to liquids of extremely low viscosity [1]. 

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. 

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