Naphthalenes commercial production

The commercial product, m.p. 53-55°, may be used. Alternatively the methyl -naphthyl ketone may be prepared from naphthalene as described in Section IV,136. The Friedel - Crafts reaction in nitrobenzene solution yields about 90 per cent, of the p-ketone and 10 per cent, of the a-ketone in carbon disulphide solution at — 15°, the proportions ore 65 per cent, of the a- and 35 per cent, of the p-isomer. With chlorobenzene ns the reaction medium, a high proportion of the a-ketone is also formed. Separation of the liquid a-isomer from the solid p-isomer in Such mixtures (which remain liquid at the ordinary temp>erature) is readily effected through the picrates the picrate of the liquid a-aceto compound is less soluble and the higher melting. 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

The first of the benzene polycarboxyUc acids to become a commercial product was phthabc acid, mosdy in the form of the anhydride. The anhydride is obtained by the catalytic vapor-phase air oxidation of o-xylene or naphthalene. The lUPAC name of phthabc anhydride is 1,3-isobenzofurandione... 

Polychloiinated naphthalenes (PCNs) are halogenated aiomatic hydiocaibons that are no longer produced. They can be synthesized by the chlorination of naphthalene. The commercial products were graded and sold according to their chlorine content (wt %), and used as waxes and impregnants (for... 

Pulping additives such as quinoid compounds increase the yield of the pulp mass up to 4% [128]. For commercial application the most promising additives are anthraquinone (AQ) or the more convenient soluble salt of tetrahydroan-thraquinone (THAQ). If AQ or THAQ could be obtained at a price below 2/kg it would find a substantial market as a pulping additive [129], Commercial production of THAQ is now based on the partial thermochemical oxidation of naphthalene. In recent years, however, the lure of the pulp market has promoted several attempts to develop a process for the electrosynthesis of THAQ based on the indirect electrooxidation of naphthalene to naphthaquinone (NQ) with Ce4+, according to the stoichiometry of the reactions 1, 2 and 3. 

Finally, a few miscellaneous compounds which were identified in the Delaware River and which have not been previously reported as water contaminants will be discussed Chloro (trifluoromethyl) aniline and chloro (trifluoromethyl) nitrobenzene (no. 55 and 56) were identified in the water, they had maximum concentrations at river mile 78. Both compounds represent common sub-structures in various pesticide and dye molecules, and several of the companies located along the river have patents using these compounds (30-32j. It is possible that these compounds are actually present in the river water as such, but it is also possible that they are formed in the GC injection port by pyrolytic degradation of larger pesticide or dye molecules (see above). All three binaphthyl-sulfone isomers (no. 92) were identified in the river water near Philadelphia. Product literature for one of the companies in the area indicates production of condensed sulfonated polymers derived from naphthalene sulfonic acid and maleic anhydride. It seems likely that the binaphthylsulfones are formed as by-products during preparation of this commercial product. 

Perinones. The most important pigment in this family is the orange perinone, Pigment Orange 43 [4424-06-0] which is obtained by reaction of naphthalene-1,4,5,8-tetracarboxylic dianhydride with tf-phenylenediamine. The result is a mixture of the cis- and trans-isomers. The commercial product is the orange trans-compound which must be separated from the dull, bluish red cis-isomer, and then conditioned for pigment use. The pigment is fairly weatherfast and heat stable, and is used primarily in plastics and fiber applications. 

The commercial product of the dinitration melts at about 140°, and consists principally of the a- and /3-compounds. The nitration of naphthalene at very low temperatures,44 —50° to —60°,. gives good yields of the y- compound, and some of this material is undoubtedly present in the ordinary product. 

Several commercial products have been produced via Heck reactions on a scale in excess of one ton year"1 [43]. The sunscreen agent 2-ethylhexyl-p-methoxycinna-mate has been synthesized on a pilot scale by using Pd/C as the catalyst [44]. Albermarle produces Naproxen via a Heck reaction of 2-bromo-6-methoxy-naphthalene with ethylene, followed by carbonylation of the product [45]. A key step in the production of Singulair (montelukast sodium), a leukotriene receptor antagonist for treatment of asthma, is Heck reaction of methyl 2-iodobenzoate with an allylic alcohol to give a ketone [43]. 

This material is prepared by a two-step nitration of naphthalene with nitric acid. The commercial product, which is a mixture of isomers, melts above 140 °C = 276°F. It is readily soluble in benzene, xylene, and acetone and is sparingly soluble in alcohol and ether. It has been used in French explosive mixtures (schneiderites) as fuel mixed with ammonium nitrate. 

Amid-Thin (naphthalene acetamide) is labeled Danger because of the potential of severe irreversible eye damage, whereas Fruitone N, NAA 800, and Tree-Hold Sprout Inhibitor (NAA) are relatively nontoxic (Category III). See Table 5.28 for a listing of commercial products. 

Scope of the Problem. Petroleum hydrocarbons are the principal components in a wide variety of commercial products (e.g., gasoline, fuel oils, lubricating oils, solvents, mineral spirits, mineral oils, and crude oil). Because of widespread use, disposal, and spills, environmental contamination is relatively common. It is important to understand that petroleum products are complex mixtures, typically containing hundreds of compounds. These include various amounts of aliphatic compounds (straight-chain, branched-chain, and cyclic alkanes and alkenes) and aromatic compounds (benzene and alkyl benzenes, naphthalenes, and PAHs). In addition, many petroleum products contain nonhydrocarbon additives such as alcohols, ethers, metals, and other chemicals that may affect the toxicity of the mixture. 

Polydimethylsiloxane in itself is very stable to near-UV light. Commercial products, however, become yellow and evolve gases on exposure to UV irradiation. This phenomenon seems to be due to photosensitized decomposition of polymers. In connection with this, Siegel et al. (53) carried out ESR studies on photosensitized decomposition of polydimethylsiloxane. When this polymer containing naphthalene was irradiated at -196° C with light of wavelengths longer than 240 nm, there were observed ESR spectra due to free radicals produced by decomposition of polymers and due to the photo-excited triplet state of naphthalene molecules. The ESR spectrum due to the free radicals observed immediately after irradiation is shown in Fig. 25a. Fig. 25b... 

Liquid. Slight odor resembling menthol. Pure Decalin does not smell of naphthalene. Volatile with steam. The commercial product may be practically all tram-Decalin, or a mixture contg up to 60% cis-Decalin. The commercial mixture has a flash pt (closed cup) of about 136 F (58 0. Autoignition temp 504 F. lnsol in water very sol in alcohol, methanol, ether, chloroform. Miscible with propyl and isopropyl alcohol miscible with most ketones and esters. LDM orally in rats 4.2 g/kg. Lethal conen for rats in air 500 ppm, Smyth er al.. Arch. Ind. Hyg Occup. Med. 4, 119 (1951). 

Anthracene—CmHid—178—exists as a constituent of coal-tar, and is obtained by expression from the substance remaining in. the still after the distillation of naphthalene, etc. The commercial product thus obtained is a yellowish mass containing 50-80-per cent, of anthracene, the purification of which is a matter of considerable difficulty. It has also been obtained synthetically, by the action of the heat on benzyl toluene, and in other ways. 

Polychlorinated naphthalenes (PCNs) have recently received increased attention [136]. In contrast with PCBs, PCNs have not been in widespread use for many years and their levels in the environment are likely lower than those of the PCBs. Sources of CNs are the commercial products, but CNs are also present as impurities in commercial PCBs and may be formed during incineration of municipal waste and in electrochemical processes based on graphite electrodes. CNs at 7.6 ng/g dry weight were found in one sediment sample from the Baltic. 

Very recently, BASF AG applied for patents on UV absorbers based on 4-cyano-naphthalene-dicarboximide derivatives, such as 4-cyano-N(2,6-diisopropylphenyl)naphthalene-l,8-dicarboximide [139], and pyridindione derivatives such as 1,4-dimethyl-5-dimethylaminomethylene-2,6-dioxo-3-cy ano-1,2,5,6-tetrahydropyridine [140]. It remains to be seen how the patenting process will proceed, and whether a commercial product will result. 

Commercial production of phthalic anhydride (PA) was taken up by BASFm 1872, by the oxidation of naphthalene with manganese dioxide and hydrochloric acid, to obtain the required base material (PA) for the manufacture of the dyestuffs fluorescein and eosine, and later for phenolphthalein however, the yield was only 5 to 7%. 

Decahydronaphthalene - hI-( )dro- naf-tho- len (Decalin ) n. A saturated bicyclic hydrocarbon, CioHig, essentially two cyclohexane rings fused together, sharing two hydrogen atoms. The commercial product is a mixture of cis- and trans-isomers. It is a colorless liquid with an aromatic odor, derived by treating molten naphthalene with hydrogen in the presence of a catalyst. 

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