Naphthalene 8-Naphthol

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. 

The xanthate transfer process provides a simple and uniquely powerful route to a-tetralones, another family of important aromatic derivatives [69-71]. a-Tetralones are starting materials for the synthesis of a host of medicinally important compoimds. They are precursors to naphthalenes, naphthols, naphthylamines, and ring expansion through the Beckmann rearrangement provides access to benzazepine derivatives. The two examples in Scheme 34 illustrate, on one hand, the possibility of preparing a tetralone with a carbohydrate-derived appendage [69] and, on the other, the synthesis of a substituted naphthol 59 by aromatisation of tetralone 58 through acid... 

This synthesis is applicable to many aromatic compounds, including alkoxyl or N,N dimethylamino derivatives of benzene and naphthalene, naphthols, indole, and certain reactive hydrocarbons, namely, anthra-cene, 1,2-benzanthracene, 3,4-benzpyrene, ° and pyrene. The high-melting polynuclear hydrocarbons react best in the presence of a solvent, such as o-dichlorobenzene. For example, a solution of anthracene, methyl formanilide, and phosphorus oxychloride in o-dichlorobenzene is heated 1 hour at 90-95° then an aqueous solution of sodium acetate is added, and the solvent and N-methylaniline are removed by steam distillation. The solid residue is readily purified to yield 9-anthraldehyde (84%). With liquid or low-melting compounds a solvent is not required. 

The nitro substitution products of naphthalene are easily prepared by the action of nitric acid on the hydrocarbon. By such direct nitration the product obtained is alpha-nitro naphthalene. This is proven by the following series of reactions. Nitro-naphfhalene by reduction yields amino naphthalene, naphthylamine, which by the diazo reaction yields hydroxy naphthalene, naphthol. Now the naphthol so obtained is identical with the one resulting from the phenyl vinyl acetic acid synthesis (p. 768) and this must be the alpha compound. 

Methacryllc Acid Methyl Alcohol Methyl Ethyl Ketone Methyl Methacrylate Naphthalene Naphthols ... 

Figure 4.7a shows the temperature-concentration phase diagram for the system naphthalene-/ -naphthol, which forms a continuous series of solid solutions. The melting points of pure naphthalene and -naphthol are 80 and 120 °C, respectively. The upper curve is the liquidus or freezing point curve, the lower the solidus or melting point curve. Any system represented by a point above the liquidus is completely molten, and any point below the solidus represents a completely solidified mass. A point within the area enclosed by the liquidus and solidus curves indicates an equilibrium mixture of liquid and solid solution. Point X, for instance, denotes a liquid of composition L in equilibrium with a solid solution of composition S, and point Y a liquid F in equilibrium with a solid S. ... 

Schaffer s acid, CioHg04S. 2-hydroxy-7-naphthalene sulphonic acid. Obtained by sulphonating 2-naphthol with a small amount of sulphuric acid at a higher temperature than is used for the preparation of crocein acid. A valuable dyestuff intermediate. 

Effect of impurities upon the melting point. Let us take a specific example and examine the effect of the addition of a small quantity of naphthalene to an equilibrium mixture of pure solid and liquid a-naphthol at the temperature of the true melting point (95 5°) at atmospheric pressure. 

The naphthalene wUl dissolve in the liquid a-naphthol and, according to Raoult s law, the vapour pressure of the latter will be reduced. Hence a-naphthol will pass preferentially into the liquid phase and, if the external temperature is maintained at 95 5°, the ultimate result will be the complete melting of the solid a-naphthol since melting requires heat and no heat is imparted to the system, the temperature will fall. 

A somewhat different method of plotting the results will help the reader to appreciate the significance of the eutectic temperature. In Fig. 1,11, 2 melting points are plotted against composition. The curve AC portrays the decreasing melting point of a-naphthol as naphthalene is added up to a mol fraction of 0 605. The curve BG represents the... 

Supplement (combined with Volume XII) XI, 2nd 1933 1605-1739 2. Sulphonic acids Benzenesulphonic acid, 26. p-Toluenesulphonic acid, 97. Naphthalene - sulphonic acid, 155. Hydroxy-Sulphonic acids Phenol-sulphonic acid, 234. Naphthol-sulphonic... 

The enone 807 is converted into the dienol triflatc 808 and then the conjugated diene 809 by the hydrogenolysis with tributylammonium for-mate[689,690]. Naphthol can be converted into naphthalene by the hydrogenolysis of its triflate 810[691-693] or sulfonates using dppp or dppf as a ligand[694]. Aryl tetrazoyl ether 811 is cleaved with formic acid using Pd on carbon as a catalyst[695]. 

The common names for the two hydroxy derivatives of naphthalene are 1 naph thol and 2 naphthol These are also acceptable lUPAC names... 

Sulfonation. Sulfonation of naphthalene with sulfuric acid produces mono-, di-, tri-, and tetranaphthalenesulfonic acids (see Naphthalene derivatives), ah of the naphthalenesulfonic acids form salts with most bases. Naphthalenesulfonic acids are important starting materials in the manufacture of organic dyes (15) (see Azo dyes). They also are intermediates used in reactions, eg, caustic fusion to yield naphthols, nitration to yield nitronaphthalenesulfonic acids, etc. 

Nitration. Naphthalene is easily nitrated with mixed acids, eg, nitric and sulfuric, at moderate temperatures to give mostly 1-nitronaphthalene and small quantities, 3—5%, of 2-nitronaphthalene. 2-Nitronaphthalene [581-89-5] is not made in substantial amounts by direct nitration and must be produced by indirect methods, eg, the Bucherer reaction starting with 2-naphthalenol (2-naphthol [135-19-3]). However, the 2-naphthylamine [91-59-8] made using this route is a carcinogen thus the Bucherer method is seldom used in the United States. 

Oxidation. Naphthalene may be oxidized direcdy to 1-naphthalenol (1-naphthol [90-15-3]) and 1,4-naphthoquinone, but yields are not good. Further oxidation beyond 1,4-naphthoquinone [130-15-4] results in the formation of ortho- h. h5 ic acid [88-99-3], which can be dehydrated to form phthaUc anhydride [85-44-9]. The vapor-phase reaction of naphthalene over a catalyst based on vanadium pentoxide is the commercial route used throughout the world. In the United States, the one phthaUc anhydride plant currently operating on naphthalene feedstock utilizes a fixed catalyst bed. The fiuid-bed process plants have all been shut down, and the preferred route used in the world is the fixed-bed process. 

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Naphthalenesulfonic acids are important chemical precursors for dye intermediates, wetting agents and dispersants, naphthols, and air-entrainment agents for concrete. The production of many intermediates used for making a2o, a2oic, and triphenylmethane dyes (qv) involves naphthalene sulfonation and one or more unit operations, eg, caustic fusion, nitration, reduction, or amination. 

Naphthalenesulfonic Acid. The sulfonation of naphthalene with excess 96 wt % sulfuric acid at < 80°C gives > 85 wt % 1-naphthalenesulfonic acid (a-acid) the balance is mainly the 2-isomer (P-acid). An older German commercial process is based on the reaction of naphthalene with 96 wt % sulfuric acid at 20—50°C (13). The product can be used unpurifted to make dyestuff intermediates by nitration or can be sulfonated further. The sodium salt of 1-naphthalenesulfonic acid is required, for example, for the conversion of 1-naphthalenol (1-naphthol) by caustic fusion. In this case, the excess sulfuric acid first is separated by the addition of lime and is filtered to remove the insoluble calcium sulfate the filtrate is treated with sodium carbonate to precipitate calcium carbonate and leave the sodium l-naphthalenesulfonate/7J(9-/4-J7 in solution. The dry salt then is recovered, typically, by spray-drying the solution. 

Acid-cataly2ed hydroxylation of naphthalene with 90% hydrogen peroxide gives either 1-naphthol or 2-naphthiol at a 98% yield, depending on the acidity of the system and the solvent used. In anhydrous hydrogen fluoride or 70% HF—30% pyridine solution at — 10 to + 20°C, 1-naphthol is the product formed in > 98% selectivity. In contrast, 2-naphthol is obtained in hydroxylation in super acid (HF—BF, HF—SbF, HF—TaF, FSO H—SbF ) solution at — 60 to — 78°C in > 98% selectivity (57). Of the three commercial methods of manufacture, the pressure hydrolysis of 1-naphthaleneamine with aqueous sulfuric acid at 180°C has been abandoned, at least in the United States. The caustic fusion of sodium 1-naphthalenesulfonate with 50 wt % aqueous sodium hydroxide at ca 290°C followed by the neutralization gives 1-naphthalenol in a ca 90% yield. 

Naphthalene. Until the 1960s, the principal outlet for naphthalene was the production of phthaHc anhydride however, more recently, o-xylene has replaced naphthalene as the preferred feedstock (see Phthalic acids). Nevertheless, of the 201,000 t produced in 1994 in Japan, 73.2% was used for phthaHc anhydride production. The rest was consumed in dye stuffs manufacture and a wide variety of other uses. Naphthalene is also used to produce phthaHc anhydride in the United Kingdom, Belgium, and the C2ech RepubHc, and can be used by Koppers in the United States in time of o-xylene shortages. In Europe, the traditional uses for naphthalene have been for the manufacture of P-naphthol and for dye stuff intermediates (see Dyes and dye... 

Some primaries have articles devoted to them and their derivatives, ie, Benzoic ACID, Phenol, Salicylic acid, and Phthalic anhydride as a derivative of phthahc acid. The primary p-naphthol is discussed in Naphthalene derivatives. 

Fusion/Hydroxylation. The conversion of arylsulfonic acids to the corresponding hydroxy compound is normally effected by heating with caustic soda (caustic fusion). The primary examples are P-naphthol in the naphthalene series and resorcinol in the benzene series further examples are m- am in oph en o1 from metanilic acid and diethyl-y -arninophenol from /V,/V-diethy1metani1ic acid. In the naphthalene series the hydroxy group is much... 

Two different all-aromatic crowns have been reported ". In 1975, de Jong, Siegel and Cram reported the synthesis of a tri-binaphthyl system in which each oxygen was bound to a naphthalene ring, but aliphatic bridges were used to join the binaphthyl units. Relatives of this compound are discussed further in Sect. 3.13. The synthesis of this molecule (Structure 17, below) was not simple, but was relatively straightforward. An interesting feature of it was the use of ethyl chloroacetate followed by LAH reduction to attach ethyleneoxy units to the naphthol unit. 

This leaction is lesorted to for the reason that naphthalene forms only the n-nitro-compound with niti icacid. The method, similar to that used for prepaiing aniline from nitiobenzene, cannot, therefore, be employed for the production of /3-n.tphtliyl-.amine. u-Naphthol is mainly used foi the manufacture of yellow and orange colours (Martins and naphthol yellow) by the action of nitric acid, and are similai m constitution to picric acid (see Prep. 107). 

Naphthalene, 216 Naphthalene picrate, 217 Naphthalene sulphonaie ofsodiiim, 218-/ J-Naphthol, 219 Naphthol yellow, 224 /i Naphthyl acetate, 222 /j-Naphthyl methyl ether, 220 /-Nitracetanilide, 153 w-Nitraniline, 154 /-Nitraniline, 153 Nitric acid (fuming), 22 NitroVienzene, 142 w-Nitrobenzoic acid, 200 Nitrogen, qualitative e rimation, 2 quantitative estimation, 13 Nitrophenol, 183 Nitrosohenzene, 146 /-Nitrosodimethylaniline, 157 Niirosoplienol, 159... 

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