Naphthalenes, formation from

Davies and Warren" found that when 1,4-dimethylnaphthalene was treated with nitric acid in acetic anhydride, and the mixture was quenched after 34 hr, a pale yellow solid with an ultraviolet spectrum similar to that of a-nitro-naphthalene was produced. However, if the mixture was allowed to stand for 5 days, the product was i-methyl-4 nitromethylnaphthalene, in agreement with earlier findings. Davies and Warren suggested that the intermediate was 1,4-dimethyl-5 nitronaphthalene, which underwent acid catalysed rearrangement to the final product. Robinson pointed out that this is improbable, and suggested an alternative structure (iv) for the intermediate, together with a scheme for its formation from an adduct (ill) (analogous to l above) and its subsequent decomposition to the observed product. 

Naphthalene (qv) from coal tar continued to be the feedstock of choice ia both the United States and Germany until the late 1950s, when a shortage of naphthalene coupled with the availabihty of xylenes from a burgeoning petrochemical industry forced many companies to use o-xylene [95-47-6] (8). Air oxidation of 90% pure o-xylene to phthaUc anhydride was commercialized ia 1946 (9,10). An advantage of o-xylene is the theoretical yield to phthaUc anhydride of 1.395 kg/kg. With naphthalene, two of the ten carbon atoms are lost to carbon oxide formation and at most a 1.157-kg/kg yield is possible. Although both are suitable feedstocks, o-xylene is overwhelmingly favored. Coal-tar naphthalene is used ia some cases, eg, where it is readily available from coke operations ia steel mills (see Steel). Naphthalene can be produced by hydrodealkylation of substituted naphthalenes from refinery operations (8), but no refinery-produced napthalene is used as feedstock. Alkyl naphthalenes can be converted directiy to phthaUc anhydride, but at low yields (11,12). 

The formation of the naphthalene (73) from the bis-ylide (72) and diethyl ketomalonate involves an unusual olefin synthesis on the carbonyl of an ester group. The methylene-pyrans (75) were formed when the diethyl malonates (74) were refluxed with j3-keto-ylides in xylene or decalin. Possible intermediates are the ketens (76) and the allenes (77). Addition of ylide to the allenes gives the betaines (78) which form methylene-pyrans either directly or via acetylenes as shown. 

Tri-(l-naphthyl)phosphine is cleaved by alkali metals in THF solution. " Reaction with sodium gives the naphthalene radical-ion, with lithium the perylene radical-ion, and with potassium the radical-ion (22). Hydrocarbon radical-ion formation was thought to occur via naphthalene derived from the metal naphthalenide. E.s.r. spectra of further examples of phosphorus-substituted picrylhydrazyl radicals have been reported. ... 

This silylene formation from 27 under mild conditions permits the synthesis of a variety of interesting carbo- and heterocycles, most of which are new types of compounds. The results are summarized in Schemes 5 and 6. The reactions with benzene and naphthalene represent the first examples of [2+1] cycloadditions of a silylene with aromatic C=C double bonds.59 623 The reactions with carbon disulfide and isocyanide (Scheme 6) are also of great interest because of their unusual reaction patterns.62b... 

In the present estimation, a continuous dehydrogenation reactor in which decalin is supplied to the catalyst at various feed rates without internal refluxing is assumed. Here all the condensable products and unconverted decalin were removed from the reactor to the condensation part (see Figure 13.22). Now, the stationary rates of hydrogen generation (VH), naphthalene formation (VN), and evaporation of unconverted decalin (VD) are defined as the magnitudes per area of the catalyst layer (mol/m2h). All these rates are expressed from mass balance as follows . 

For the SPE of the more polar aromatic sulfonates, IPs with tetralkylammonium are previously formed [85,93,94]. The combination of the formation of IP with cetyltrimethylammonium and SPE is efficacious in the extraction of benzene and naphthalene sulfonates from an aqueous environment. Good recoveries are also obtained with octylammonium acetate as the IP agent, both when it is added to the aqueous sample prior to the extraction and when it saturates the solid phase to produce an anion-exchange column [95,96]. An alternative approach is based on the use of deactivated charcoal (Carbonpack B) [96] or of chemically modified polystyrene-divinylbenzene resins [85]. Often graphitized carbon black (GCB) is used for the clean-up process of the sample [96]. 

The formation of norcaradiene derivatives with naphthalene [reaction (22)] lends some support to this scheme. This mechanism resembles a bimolecular two-step process suggested for the reaction of chloromethyl-aluminum compounds with olefins (199-201). On the other hand, a bimolecular one-step methylene transfer mechanism is generally accepted for the formation of cyclopropane derivatives by the reaction of halo-methylzinc compounds with olefins. This difference between the mechanism proposed for the cyclopropane formation from olefin and that for the ring expansion of aromatic compound may be ascribable to the difference in the stability of intermediates the benzenium ion (XXII) may be more stable than an alkylcarbonium ion (369). 

The 1,2-cycloaddition reaction can take place in an intramolecular manner (equation 63), although in this example the initial excitation involves the aromatic group . A reaction of a different type is thought to be involved in the first stage of the formation of azulene or naphthalene photodimers from diphenylacetylene (equation 64), though here it is claimed that an intermediate benzocyclobutadiene species has been detected . The intermediate isomer of diphenylacetylene is formed via the triplet state and is relatively long-lived at — 10 °C. The major dimers formed are 1,2,3-triphenylazulene and 1,2,3-triphenylnaphthalene hexaphenylbenzene and octaphenylcubane are also produced . 

The CnH2n-i2 shows an increase in relative concentration of naphthalenes going from the Noonan lignite to the Loveridge coal. Cadalene was identified only in the Noonan, Wyodak, and Hiawatha samples. Bendoritas (5) first identified cadalene in three crudes from the Jackson Sands formation in Texas. He suggested naturally occurring cadinene as a possible precursor. 

Character of Center Nucleus.—As was stated in connection with anthracene itself we can not say positively as to the character of the center nucleus in either the hydrocarbon or the quinone. In anthracene the aliphatic character of this center nucleus is indicated by its formation from an ethane residue, by the tetra-brom ethane synthesis. This does not, however, preclude the possibility of its becoming a true benzene nucleus when condensed with two benzene rings, for benzene itself may be made from aliphatic hydrocarbons, from acetylene by polymerization (p. 478), and from hexane through hexa-methylene with the loss of hydrogen after the formation of the cyclo-paraffin (p. 469). Also naphthalene, in which there is no doubt of the benzene character of the two nuclei, may have one nucleus formed from an aliphatic chain as in the syntheses given (p. 767) from phenyl butylene bromide, from phenyl vinyl acetic acid and from tetra-carboxy ethane. In the same way the facts in regard to anthraquinone do not prove... 

DM Jerina, JW Daly, B Witkop, P Zaltzaman-Nirenberg, S Udenffiend. The role of arene oxide-oxepin systems in the metabolism of aromatic substrates. III. Formation of 1,2-naphthalene oxide from naphthalene in microsomes. J Am Chem Soc 90 6525-6527, 1968. 

Attention has been drawn in Section 4.4.2 to the ability of naphthalene dioxygenase from Pseudomonas sp. strain 9816-4 to produce dibenzothiophene a s-l,2-dihydrodiol (Resnick and Gibson 1996). The transformation of naphtho[2,l-fr]thiophene and naphtho[2,3-fr]thiophene by Pseudomonas sp. strains grown with 1-methylnaphthalene has been examined (Knopp et al. 1997) as for the corresponding PAHs, the angular substrate (naphtho[2,l-b]thiophene) was more readily tranformed with the formation of hydroxybenzothiophene carboxylates by dioxygenation of the outer benzene ring followed by extradiol fission. 

Regioselective monoalkyl ether formation from naphthalene-1, 4-diols using alcohols (prim, or sec.) containing HCI. 

According to different mechanisms of coke formation, we have observed different products of polycondensation using chromatographic, luminiscent, and UV-spectroscopic methods. For example, in the case of decomposition of benzene on different catalysts only products of the dehydrocondensation of benzene with preservation of nuclei were observed (biphenyl, biphenylbenzenes, triphenylene, products of condensation of more than four benzene nuclei, etc.) and such products as naphthalene, anthracene, and phenanthrene were not observed. In tar and coke formation from ethylene on silica gel and aluminosilicates the formation of naphthalene, chrysene, 1,2-dibenzanthracene, fluorene, its derivatives, and others, takes place and if the process is carried out on alumina at a temperature lower than 500°, mainly anthracene, phenanthrene, pyrene, and coronene are formed, but aliphatic hydrocarbons, etc., do not appear. 

Triplet sensitization of sulfonium salts proceeds exclusively by the homolytic pathway, and that the only arene escape product is benzene, not biphenyl or acetanilide. However, it is difficult to differentiate between the homolytic or heterolytic pathways for the cage reaction, formation of the isomeric halobiaryls. Our recent studies on photoinduced electron transfer reactions between naphthalene and sulfonium salts, have shown that no meta- rearrangement product product is obtained from the reaction of phenyl radical with diphenylsulfinyl radical cation. Similarly, it is expected that the 2- and 4-halobiaryl should be the preferred products from the homolytic fragments, the arene radical-haloarene radical cation pair. The heterolytic pathway generates the arene cation-haloarene pair, which should react less selectively and form the 3-halobiaryl, in addition to the other two isomers. The increased selectivity of 2-halobiaryl over 3-halobiaryl formation from photolysis of the diaryliodonium salts versus the bromonium or chloronium salts, suggests that homolytic cleavage is more favored for iodonium salts than bromonium or chloronium salts. This is also consistent with the observation that more of the escape aryl fragment is radical derived for diaryliodonium salts than for the other diarylhalonium salts. 

Aromatic systems have always attracted considerable attention. Eremenko et al. [107,108], choosing naphthalene and naphthylamine as probe molecules in alkah metal and alkaline earth ion-exchanged faujasites, investigated the formation of donor-acceptor complexes and the oxidation of naphthalene using luminescence and DR spectra. Naphthalene adsorbed from hexane solution in... 

However, this pathway could not account for the formation of a-methyl naphthalene formed from 2-methylazulene unless naphthalene was produced sufficiently vibrationally hot to undergo some isomerization. 

Evidence for the intermediacy of carbenes in these dehalogenations comes from the isolation of (851) when (850) is treated with sodium naphthalene (NaNp), from the formation of cyclobutanones via oxaspiropentanes when gfcm-dihalogenocyclo-propanes are treated with BuLi in the presence of ketones, and from the intramolecular trapping of the carbene by a double bond in an olefinic or allenic dibro-mocyclopropane. 

In order to accommodate the later kinetic data, 77-complex formation from the diprotonated substrate had to be introduced , despite a previous theoretical demonstration that this was improbable. As the earlier versions of the theory also could not account for the kinetic order of the reaction of hydrazo-naphthalene and of semidine- and diphenyline-forming rearrangements , or for the products and kinetics for compounds with bulky para substituents , and furthermore, led to incorrect general rules for products, there seems little justification for its continued advocacy. The latest version of the theory has been stripped of its quantitative content, and is little more than a statement that the reaction is intramolecular and has some kind of (unspecified) interaction between the different potential fragments, as they readjust their relative positions. 

---