The Oxidation of Naphthalene

Prepared by the oxidation of naphthalene with sulphuric acid at 270-300 C in the presence of HgSO under these conditions the... 

Manufacture and Processing. Until World War II, phthaUc acid and, later, phthaUc anhydride, were manufactured primarily by Hquid-phase oxidation of suitable feedstocks. The favored method was BASF s oxidation of naphthalene [91-20-3] by sulfuric acid ia the presence of mercury salts to form the anhydride. This process was patented ia 1896. During World War I, a process to make phthaUc anhydride by the oxidation of naphthalene ia the vapor phase over a vanadium and molybdenum oxide catalyst was developed ia the United States (5). Essentially the same process was developed iadependendy ia Germany, with U.S. patents being granted ia 1930 and 1934 (6,7). 

Fixed-Bed Vapor-Phase Oxidation of Naphthalene. A sihca gel or sihcon carbide support is used for catalyst involved in the oxidation of naphthalene. The typical naphthalene oxidation catalyst is a mixture of vanadium oxide and alkali metal sulfate on the siUca support. Some changes, such as the introduction of feed vaporizers, are needed to handle a naphthalene feed (14), but otherwise the equipment is the same. 

Jeffrey AM, HJC Yeh, DM Jerina, TR Patel, JF Davey, DT Gibson (1975) Initial reactions in the oxidation of naphthalene by Pseudomonas putida. Biochemistry 14 575-584. 

I, 4-benzoquinone.4 Other methods that have been employed include the oxidation of naphthalene with hydrogen peroxide,5 the oxidation of 1,4-naphthalenediamine 6 and naphthylamine sulfonic acid 7 and the oxidation of 4-amino-1-naphthol prepared by electrolytic reduction of 1-nitronaphthalene.8... 

The following model is proposed for the oxidation of naphthalene in a tubular flow reactor with constant wall temperature (Welsenaere Froment, Chem Eng Science 25 1503, 1970) ... 

Fluidised catalysts are also used in the synthesis of high-grade fuels from mixtures of carbon monoxide and hydrogen, obtained either by coal carbonisation or by partial oxidation of methane. An important application in the chemical industry is the oxidation of naphthalene to phthalic anhydride, as discussed by Riley(131). The kinetics of this reaction are much slower than those of catalytic cracking, and considerable difficulties have been experienced in correctly designing the system. 

Tuhkanen, T.A. and Beltran, F.J. Intermediates in the oxidation of naphthalene in water with the combination of hydrogen peroxide and UVradiation, Chemosphere, 30(8) 1463-1475, 1995. 

Phthalic acid (1,2-benzene dicarboxylic acid), isophthalic acid (1,3-benzene dicarboxylic acid), and terephthalic acid (1,4-benzene dicarboxylic acid) are made by the selective oxidation of the corresponding xylenes. Terephthalic acid may also be produced from the oxidation of naphthalene and by the hydrolysis of terephthalonitrile. 

So far, no reference has been made to the presence of more than one phase in the reactor. Many important chemicals are manufactured by processes in which gases react on the surface of solid catalysts. Examples include ammonia synthesis, the oxidation of sulphur dioxide to sulphur trioxide, the oxidation of naphthalene to phthalic anhydride and the manufacture of methanol from carbon monoxide and hydrogen. These reactions, and many others, are carried out in tubular reactors containing a fixed bed of catalyst which may be either a single deep bed or a number of parallel tubes packed with catalyst pellets. The latter arrangement is used, for exjimple, in the oxidation of ethene to oxiran (ethylene oxide)... 

Three well known examples of processes employing fluidised-bed operations are the oxidations of naphthalene and xylene to phthalic anhydride using a supported V2O5 catalyst and ammoxidation of propylene utilising a mixed oxide composition containing bismuth molybdate. Typically, this latter reaction is executed by passing a mixture of ammonia, air and propylene to a fluidised bed operating at about 0.2 MPa pressure, 400—500°C and a few seconds contact time between gas and fluidised catalyst peirticles. 

With a particular catalyst and at a given temperature, the oxidation of naphthalene to phthalic anhydride proceeds as follows ... 

The oxidation of naphthalene was one of the earliest examples of an epoxide as an intermediate in aromatic hydroxylation. The epoxide can rearrange nonenzymatically to yield predominantly 1-naph-thol, interact with the enzyme epoxide hydrolase to yield the dihydrodiol, or interact with glutathione S-transferase to yield the glutathione conjugate, which is ultimately metabolized to a mer-capturic add. 

A typical reaction network for the oxidation of naphthalene includes naphthoquinones as intermediates1006 1033 (Scheme 9.27). 

Orthophthalic acid is made by the oxidation of naphthalene (1) with H2SCL fuming heated, in the presence of mercuric sulfate —SO2 is also formed and recovered (2 ) with air in the presence of vanadium pentoxide at 450 to 520°C. Orthophthalic acid also is formed when benzene compounds containing carbon ortho-substituted groups are oxidized. Orthophthalic arid is used in the manufacture of indigo and other dyes,... 

Oxides Vanadium monoxide VO, gray solid vanadium trioxide V2O3, black solid vanadium dioxide VO2, dark blue solid vanadium pentoxide V2O5, orange to red solid. The last is the most important oxide formed by the ignition in an of vanadium sulfide, 01 othei oxide, 01 vanadium used as a catalyzer, e.g., the reaction SO2 gas plus oxygen of air to form sulfur tnoxide. and the oxidation of naphthalene by air to form phthalie anhydride. 

Naphthoquinone has been prepared by the oxidation of naphthalene,1 1,4-aminonaphthol,2 1,4-naphthylene diamine,2 and 1,4-naphthylamine sulfonic acid.3 Recent work4 has shown that the oxidation of the 1,4-aminonaphthol is the most convenient method of preparation. 

As an oxidant, mercury may be used in the presence of sulphuric acid. One of the most important examples of this is the oxidation of naphthalene to phthalic acid, nsed on the large scale in the first stage of the process for preparing indigo from tin hydrocarbon. 

Naphthalene-1,2-oxide is a metabolic intermediate in the oxidation of naphthalene mediated by cytochrome P-450. 

The following first-order consecutive-parallel reaction scheme is used, which is in accord with the oxidation of naphthalene (1) ... 

Other catalytic reactions carried out in fluidized-bed reactors are the oxidation of naphthalene to phthalic anhydride [2, 6, 80] the ammoxidation of isobutane to mcthacrylonitrilc [2] the synthesis of maleic anhydride from the naphtha cracker C4 fraction (Mitsubishi process [81, 82]) or from n-butane (ALMA process [83], [84]) the reaction of acetylene with acetic acid to vinyl acetate [2] the oxychlorination of ethylene to 1,2-di-chloroethane [2, 6, 85, 86] the chlorination of methane [2], the reaction of phenol with methanol to cresol and 2,6-xylenol [2, 87] the reaction of methanol to gasoline... 

Phthalic Anhydride. Although phthalic anhydride first was made commercially from the oxidation of naphthalene, by 1999, nearly 90 percent of the production had been converted to o-xylene as the feedstock. This is now essentially the only major use for the o-xylene. The flowsheet in Fig. 10.37 shows a typical process... 

The oxidation of naphthalene to phthalic anhydride has long been its principal end use. In the last 30 years, however, o-xylene has supplanted naphthalene as the preferred raw material for phthalic anhydride, and it now accounts for about 90 percent of the PA production. The manufacture of phthalic anhydride is described above in the section Chemicals from Xylene. ... 

The commercial preparation of anthraquinone dyes begins with the synthesis of anthraquinone itself. In this regard, the three-step synthesis involves (1) the oxidation of naphthalene to phthalic anhydride, (2) Friedel-Crafts acylation of benzene to give a keto acid, and (3) cyclodehydration using H2S04. See Fig. 13.110. The preparation of 1,4-disubstituted anthraquinones utilizes the intermediates... 

Oxidation of arenes This oxidant is somewhat superior to CrOs for oxidation of arenes to quinones but less efficient than ceric ammonium sulfate (8,80-81). An example is the oxidation of naphthalene to 1,4-naphthoquinone in 75% yield. 

This is exactly analogous to the oxidation of naphthalene to ortho-phthalic acid and the conversion of this into benzene (p. 689). 

Acid anhydrides as activated derivatives of carboxylic acids have found little attention for the preparation of acid halides. Their use can be justified if they are obtained from other sources than from carboxylic acids, e.g. phthalic anhydride from the oxidation of naphthalene or o-xylene. It is, therefore, no surprise that there exist patents to convert phthalic anhydride to phthalic acid dichloride with carbonyl dichloride in the presence of catalysts. " However, there are some methods available thus a,a-di-chloromethyl methyl ether will convert acid anhydrides to acid chlorides and brenzcatechyl phosphorus tribromide will also achieve this transformation. Fluorides may be prepared similarly with the pyridine/HF mixture of 01ah. °... 

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