1.2.3.4- tetrahydronaphthalene naphthalene

A further example is given below illustrating the use of a dibasic anhydride (succinic anhydride) the succinoylation reaction is a valuable one since it leads to aroyl carboxylic acids and ultimately to polynuclear hydrocarbons. This general scheme of synthesis of substituted hydrocarbons through the use of succinic anhydride is sometimes called the Haworth reaction. Thus a-tetralone (see below) may be reduced by the Clemmensen method to tetralin (tetrahydronaphthalene) and the latter converted into naphthalene either catal3d.ically or by means of sulphur or selenium (compare Section, VI,33). 

Eriedel-Crafts reaction of naphthalene or tetrahydronaphthalene derivatives with those of styrene or alkylbenzenes has been used in the preparation of high viscous fluids for traction drive (195). Similarly, Eriedel-Crafts reaction of tetraline and a-methylstyrene followed by catalytic hydrogenation provided l-(l-decalyl)-2-cyclohexyl propane, which is used as a highly heat resistant fluid (196). 

Naphthalene is very slightly soluble in water but is appreciably soluble in many organic solvents, eg, 1,2,3,4-tetrahydronaphthalene, phenols, ethers, carbon disulfide, chloroform, ben2ene, coal-tar naphtha, carbon tetrachloride, acetone, and decahydronaphthalene. Selected solubiUty data are presented in Table 4. 

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. 

Tetrahydronaphthalene dehydrogenates to naphthalene at 200—300°C in the presence of a catalyst thermal dehydrogenation takes place at ca 450°C and is accompanied by cracking to compounds, such as toluene and xylene. 

Tetrahydronaphthalene is produced by the catalytic treatment of naphthalene with hydrogen. Various processes have been used, eg, vapor-phase reactions at 101.3 kPa (1 atm) as well as higher pressure Hquid-phase hydrogenation where the conditions are dependent upon the particular catalyst used. Nickel or modified nickel catalysts generally are used commercially however, they are sensitive to sulfur, and only naphthalene that has very low sulfur levels can be used. Thus many naphthalene producers purify their product to remove the thionaphthene, which is the principal sulfur compound present. Sodium treatment and catalytic hydrodesulfuri2ation processes have been used for the removal of sulfur from naphthalene the latter treatment is preferred because of the ha2ardous nature of sodium treatment. 

Miscellaneous uses include several organic compounds and intermediates, eg, 1-naphthalenol, 1-naphthylamine [134-32-7] 1,2,3,4-tetrahydronaphthalene, decahydronaphthalene, and chlorinated naphthalenes. 

MNN is obtained in 3—5% yield by the nitration of naphthalene and is present at this level in coml MNN. It is best prepd by indirect methods for example, by the removal of an amino group from an appropriately substituted nitro-naphthylamine. The amine is treated with Na nitrite and acid to form the diazonium salt which is replaced with a H atom by redn with EtOH (Ref 7). It may also be prepd by treatment of 6-nitro-l, 2,3,4-tetrahydronaphthalene with Br to form a dibromo compn (probably the 1,4-isomer), followed by removal of two moles of H bromide by distn in the presence of base (Ref 10). 2-Naphthalenediazonium fluoroborate... 

Partial reduction of polyarenes has been reported. Use of boron trifluoride hydrate (BF3 OH2) as the acid in conjunction with triethylsilane causes the reduction of certain activated aromatic systems 217,262 Thus, treatment of anthracene with a 4-6 molar excess of BE3 OH2 and a 30% molar excess of triethylsilane gives 9,10-dihydroanthracene in 89% yield after 1 hour at room temperature (Eq. 120). Naphthacene gives the analogously reduced product in 88% yield under the same conditions. These conditions also result in the formation of tetralin from 1-hydroxynaphthalene (52%, 4 hours), 2-hydroxy naphthalene (37%, 7 hours), 1-methoxynaphthalene (37%, 10 hours), 2-methoxynaphthalene (26%, 10 hours), and 1-naphthalenethiol (13%, 6 hours). Naphthalene, phenanthrene, 1-methylnaphthalene, 2-naphthalenethiol, phenol, anisole, toluene, and benzene all resist reduction under these conditions.217 Use of deuterated triethylsilane to reduce 1-methoxynaphthalene gives tetralin-l,l,3-yielding information on the mechanism of these reductions.262 2-Mercaptonaphthalenes are reduced to 2,3,4,5-tetrahydronaphthalenes in poor to modest yields.217 263... 

When naphthalene (2 mg/L) in hydrogen-saturated deionized water was exposed to a slurry of palladium catalyst (1 g/L Pd on alumina) at room temperature for 35 min, 95% was converted to tetrahydronaphthalene (Schiith and Reinhard, 1997). 

Uses Intermediate for phthalic anhydride, naphthol, 1,4-naphthoquinone, 1,4-dihydro-naphthalene, 1,2,3,4-tetrahydronaphthalene (tetralin), decahydronaphthalene (decalin), 1-nitro-naphthalene, halogenated naphthalenes, naphthol derivatives, dyes, explosives mothballs manufacturing preparation of pesticides, fungicides, detergents and wetting agents, synthetic resins, celluloids, and lubricants synthetic tanning preservative emulsion breakers scintillation counters smokeless powders. 

Tetrachloroterephthalic, see Chlorthal-dimethyl Tetraethyl monothiopyrophosphate, see Diazinon Tetraethyl p3U ophosphate, see Diazinon Tetrahydrodicyclopentadiene, see Chlordane Tetrahydronaphthalene, see Naphthalene... 

Depending on the catalysts, catalytic hydrogenation converts naphthalene to tetrahydronaphthalene (tetralin), or cis- or trons-decalin (decahydro-naphthalene) [S, 405, 406, 407]. Tetrahydronaphthalene was converted to ciy-decalin by hydrogenation over platinum oxide [S]. 

In another paper from the Jackson Laboratories of the du Pont Company (Calcott et al., 34) there is reported a repetition of some of the reactions of Simons and Archer, as well as additional ones. Mono-, di-, and 1,2,4,5 tetraisopropylbenzene were obtained from propylene and benzene both l -chloro-i-butylbenzene and di-(l/-chloro)-d-butylben-zene were obtained from 3-chloro-2-methyl-propene-l and benzene p-f-butyltoluene and di-i-butyltoluene were obtained from diisobutylene and toluene tetraisopropylnaphthalene was obtained from propylene and naphthalene naphthyl-stearic acid was obtained from oleic acid and naphthalene mixed isopropyltetrahydronaphthalene was obtained from propylene and tetrahydronaphthalene 2,4,6-triisopropylphenol was obtained from propylene and phenol a mixture of monoisopropylated m-cresols was obtained from propylene and wi-cresol and di-(s-hexyl)-diphenyl oxide was obtained from hexene-3 and diphenyl oxide. 

Methoxy-7-methoxycarbonyl-1,2,3,4-tetrahydronaphthalene 2-Naphthalene-carboxylic acid, 5,6,7,8-tetrahydro-3-methoxy-, methyl ester (78112-34-2), 65, 98 Methyl acrylate (96-33-3), 66, 54, 59 dimerization by Pd(II), 66, 52 Methylamine, N-benzylidene-, 65, 140 METHYL 4-0-BENZOYL-6-BROMO-6-DEOXY-a-0-GLUCOPYRANOSIDE ... 

With the above data, it is possible to establish the molecular formula, and, by proper analysis, combination, and correlation of these data with values for known pure compounds, to determine the type of hydrocarbons constituting the homogeneous mixture, as paraffin, cycloparaffin, dicycloparaffin, benzene derivative, naphthalene derivative, tetrahydronaphthalene derivative, etc. 

On gradual heating to 300 C with four equivalents of antimony(V) fluoride and simultaneous distillation of the reaction product, octafluoronaphthalene is transformed to perfluoro-1,2.3,4-tetrahydronaphthalene in 77% yield.94 Under similar conditions 2-substituted hepta-fluoronaphthalenes(R = H, Cl) give a mixture of octafluoronaphthalene and the corresponding 6-substituted undecafluoro-1,2,3,4-tetrahydronaphthalenes in about 40 % yield while the major fluorination product of the compound with R = CF3 is perfluoro(6-methyl-1,2,3,4-tetrahydro-naphthalene) (50%).97... 

Many of these compounds have also been fluorinated over potassium tetrafluorocobalt-ate(III) when compounds with double bonds result. Naphthalene and 1,2,3,4-tetrahydronaphthalene at 300°C give72 very similar product mixtures, the main components of which were the monoenes 17 (58%) and 18 (33%). 

The starting material for the 1,2-disubstituted tetrahydro-naphthalenes was 5,6,7,8-tetrahydro-2-naphthol. This compound was converted in low yield to the known Via by the Reimer-Tiemann reaction. VI6 and Vic both were prepared from 1-bromo-2-methoxy-5,6,7,8-tetrahydronaphthalene. Although VI6 was prepared according to the method of O Farrell et al. [3], we obtained a much higher yield,... 

Although these results cannot be interpreted as easily m those for benzene, naphthalene, and phcnanthrene, it is readily apparent that the average rir(C=0) values for Bond A are nearly the same for indan, o-xylene, and tetrahydronaphthalene the same is true for Bond B. 

Detailed studies have been conducted on the selectivity of hydrogenation of naphthalene.67 The reaction proceeds via tetrahydronaphthalene as an intermediate and eventually yields a mixture of the isomeric decalins ... 

Naphthalene can be reduced more easily than benzene. With sodium in alcohol, 1,4-dihydronaphthalene is formed. Catalytic hydrogenation gives tetralin (1,2,3,4-tetrahydronaphthalene). Further reduction to give perhydro-naphthalene (decalin) can be achieved on prolonged catalytic hydrogenation at relatively high temperatures and pressures ... 

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