Nitrobenzene, from benzene

For example, on an exam, you may be asked to prepare l-bromo-3-nitrobenzene from benzene in two steps. In this case, you must know not only what reactants to use but also the order to use them. 

The process for the production of nitrobenzene from benzene involves the use of mixed acid (Fig. 1), but there are other useful nitrating agents, e.g., inorganic nitrates, oxides of nitrogen, nitric acid plus acetic anhydride, and nitric acid plus phosphoric acid. In fact, the presence of sulfuric acid in quantity is vital to the success of the nitration because it increases the solubility of the hydrocarbon in the reaction mix, thus speeding up the reaction, and promotes the ionization of the nitric acid to give the nitronium ion (N02+), which is the nitrating species. Absorption of water by sulfuric acid favors the nitration reaction and shifts the reaction equilibrium to the product. 

Suggest syntheses of the following compounds from the starting material given (a) 4-chloro-3-nitrobenzoic acid from toluene (b) 2-chloro-4-nitrobenzoic acid from toluene (c) 4-benzylbenzoie acid from toluene (d) l-ethyl-3-nitrobenzene from benzene e) iso butyl benzene from benzene. 

The synthesis starts, then, with the generation of nitrobenzene from benzene NO ... 

Our knowledge of the mechanism of the reaction in this medium comes from an investigation of the nitration of nitrobenzene, /)-chloronitro-benzene and i-nitroanthraquinone. These compounds underwent reaction according to the following rate law ... 

Nixan [Nitrocyclohexane] A process for making cyclohexane oxime (an intermediate in the manufacture of nylon) from benzene by liquid phase nitration, followed by hydrogenation of the nitrobenzene. Invented by Du Pont and operated from 1963 to 1967. 

There is a long history of the preparation of explosive solids or oils from interaction of diazonium salts with solutions of various sulfides and related derivatives. Such products have arisen from benzene- and toluene-diazonium salts with hydrogen, ammonium, or sodium sulfides [1,5] 2- or 3-chlorobenzene-, 4-chloro-2-methylbenzene-, 2- or 4-nitrobenzene- or 1- or 2-naphthalene-diazonium solutions with hydrogen sulfide, sodium hydrogen sulfide or sodium mono-, di- or poly-sulfides [l]-[4,7], 4-Bromobenzenediazonium solutions gave with hydrogen sulfide at -5°C a product which exploded under water at 0°C [2], and every addition of a drop of 3-chlorobenzenediazonium solution to sodium disulfide solution... 

There are nine chemicals in the top 50 that are manufactured from benzene. These are listed in Table 11.1. Two of these, ethylbenzene and styrene, have already been discussed in Chapter 9, Sections 5 and 6, since they are also derivatives of ethylene. Three others—cumene, acetone, and bisphenol A— were covered in Chapter 10, Sections 3-5, when propylene derivatives were studied. Although the three carbons of acetone do not formally come from benzene, its primary manufacturing method is from cumene, which is made by reaction of benzene and propylene. These compounds need not be discussed further at this point. That leaves phenol, cyclohexane, adipic acid, and nitrobenzene. Figure 11.1 summarizes the synthesis of important chemicals made from benzene. Caprolactam is the monomer for nylon 6 and is included because of it importance. 

Another use of these reactions is in the production of amines, for example, the formation of aniline from benzene. The benzene is first nitrated in nitric acid, and then in another reactor the nitrobenzene is reduced to aniline with H2 (another use of Hz) in the reactions... 

After styrene production, approximately 20% of benzene production is used to produce cumene (isopropylbenzene), which is converted to phenol and acetone. Benzene is also converted to cyclohexane, which is used to produce nylon and synthetic fibers. Nitrobenzene derived from benzene is used to produce aniline, which has widespread use in dye production. Besides the benzene derivatives mentioned in this section, countless other products are based on the benzene ring. Cosmetics, drugs, pesticides, and petroleum products are just a few... 

Show how the following substances may be synthesized from benzene, nitrobenzene, and halogenated or alkylbenzenes, using the reactions discussed in this chapter and in Chapters 22 and 23. 

Selenodi-j8-naphthylamine separates from benzene as yellowish-green, matted needles, M.pt. 245° C., from nitrobenzene as greenish prisms, and from alcohol in tablets. Its concentrated sulphuric acid solution is blue-green. Addition of ferric chloride to its alcoholic solution gives a moss-green coloration. Nitric acid yields a yellow nitro-compound. 

The catalytic process for the production of picric acid directly from benzene in one step by the action of nitric acid in the presence of mercuric nitrate has much theoretical interest and has been applied, though not extensively, in plant-scale manufacture. It yields about as much picric acid as is procurable from the same weight of benzene by the roundabout method of sulfonating the benzene, converting the benzene sulfonic acid into phenol, and nitrating the phenol to picric acid—and the benzene which is not converted to picric acid is for the most part recovered as such or as nitrobenzene. The first mention of the process appears to be in the patent of Wolffenstein and Boeters.55... 

Cyclonite is a white crystalline solid, m.p. 202°. It is insoluble in water, alcohol, ether, ethyl acetate, petroleum ether, and carbon tetrachloride, very slightly soluble in hot benzene, and soluble 1 part in about 135 parts of boiling xylene. It is readily soluble in hot aniline, phenol, ethyl benzoate, and nitrobenzene, from all of which it crystallizes in needles. It is moderately soluble in hot acetone, about 1 part in 8, and is conveniently recrystallized from this solvent from which it is deposited in beautiful, transparent, sparkling prisms. It dissolves very slowly in cold concentrated sulfuric acid, and the solution decomposes on standing. It dissolves readily in warm nitric acid (1.42 or stronger) and separates only partially again when the liquid is cooled. The chemical reactions of cyclonite indicate that the cyclotrimethylenetri-nitramine formula which Herz suggested for it is probably correct. 

Called in Beil N-[3 Nitro-phenyl]-2,4,6-trinitropheny endiamin-( 1,3)1, H2N(02N)2-C4H-NH-C6H4 N02. Oysts(from et acet), mp 272°(decomp). Can be prepd either by heating 2,3,4,6-tetranitroaniline with 3 nitrobenzene in benzene or by fusing N-nitro N-methyl-2,4,6-trinitro-l,3-phenylenediamine with 3-nitroaniline at 110—120°. Its expl props were not reported... 

Fluorobenzene is prepared from aniline by the Schiemann reaction, shown in Section 22.18. Aniline is, of course, prepared from benzene via nitrobenzene. Friedel-Crafts acylation of fluorobenzene has been carried out with the results shown and gives the required ethyl p-fluorophenyl ketone as the major product. 

Complexes of Cr, W, Mo, Fe, Ru, V, Mn and Rh form stable, isolable arene if -complexes. Among them, arene complexes of Cr(CO)3 have high synthetic uses. When benzene is refluxed with Cr(CO)6 in a mixture of dibutyl ether and THF, three coordinated CO molecules are displaced with six-7r-electrons of benzene to form the stable i/fi-benzene chromium tricarbonyl complex (170) which satisfies the 18-electron rule (6 from benzene + 6 from Cr(0) + 6 from 3 CO = 18). Complex formation is facilitated by electron-donating groups on benzene, and no complex of nitrobenzene is formed. Complex formation has a profound effect on reactivity of arenes, and the resulting complexes are used in synthetic reactions. The metal-free reaction products can be isolated easily after decomplexation by mild oxidation using low-valent Cr. Cycloheptatriene also forms a stable complex with Cr(CO)3 and its synthetic applications are discussed below. 

The influence of the above factors on the course of the reaction has been demonstrated for intermolecular acylation. Changing the solvent from benzene to nitrobenzene in the Friedel-Crafts acetylation of naphthalene makes it possible to obtain principally the /3-isomer instead... 

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