Derivatives of benzene

Some of the common aromatics found in crude oil are the simple derivatives of benzene in which one or more alkyl groups (CHg) are attached to the basic benzene molecule as a side chain which takes the place of a hydrogen atom. These arenes are either liquids or solids under standard conditions. 

TABLE 5.2 Nitrations of mono-substituted derivatives of benzene in solutions of acetyl nitrate in acetic anhydride ... 

TABLE 5.4 Yields moles %) in the nitration and acetoxylation of some derivatives of benzene at 25 °C... 

There have been many studies of the orientation of nitration in di- and poly-substituted derivatives of benzene, but in very few cases have... 

Compounds related to benzene were obtained from similar plant extracts Eor example a pleasant smelling resin known as tolu balsam was obtained from the South American tolu tree In the 1840s it was discovered that distillation of tolu balsam gave a methyl derivative of benzene which not surprisingly came to be named... 

All compounds that contain a benzene ring are aromatic and substituted derivatives of benzene make up the largest class of aromatic compounds Many such compounds are named by attaching the name of the substituent as a prefix to benzene... 

Many simple monosubstituted derivatives of benzene have common names of long stand mg that have been retained m the lUPAC system Table 111 lists some of the most important ones... 

Dimethyl derivatives of benzene are called xylenes There are three xylene isomers the ortho (o) meta (m) and para (p) substituted derivatives... 

Names of Some Frequently Encountered Derivatives of Benzene... 

Many aromatic compounds are simply substituted derivatives of benzene and are named accordingly Many others have names based on some other parent aromatic compound... 

The scope of electrophilic aromatic substitution is quite large both the aromatic com pound and the electrophilic reagent are capable of wide variation Indeed it is this breadth of scope that makes electrophilic aromatic substitution so important Elec trophilic aromatic substitution is the method by which substituted derivatives of benzene are prepared We can gam a feeling for these reactions by examining a few typical exam pies m which benzene is the substrate These examples are listed m Table 12 1 and each will be discussed m more detail m Sections 12 3 through 12 7 First however let us look at the general mechanism of electrophilic aromatic substitution... 

Aniline is the parent lUPAC name for ammo substituted derivatives of benzene Substituted derivatives of aniline are numbered beginning at the carbon that bears the ammo group Substituents are listed m alphabetical order and the direction of number mg IS governed by the usual first point of difference rule... 

Monocyclic Aromatic Compounds. Except for six retained names, all monocyclic substituted aromatic hydrocarbons are named systematically as derivatives of benzene. Moreover, if the substituent introduced into a compound with a retained trivial name is identical with one already present in that compound, the compound is named as a derivative of benzene. These names are retained ... 

Styryl Derivatives of Benzene and Biphenyl. Othei compounds based on the styryl gioup weie piepaied to lengthen the conjugated system of stilbene. 

Commercial Disperse Azo Dyes. The first proposal to use insoluble dyes in suspension in an aqueous foam bath, ie, disperse dyes, to dye cellulose acetate was in 1921 (60). Commercialization of disperse dyes began in 1924 with the introduction of the Duranol dyes by British Dyestuffs Corporation (61) and the SRA dyes by British Celanese Company (62). In contrast to the acid monoazo dyes, derivatives of benzene rather than of naphthalene are of the greatest importance as coupling components. Among these components mono- and dialkylariifines (especially A/-P-hydroxyethyl-and A/-(3-acetoxyethylanifine derivatives) are widely used couplers. Nitrodiazobenzenes are widely used as diazo components. A typical example is CeUiton Scarlet B [2872-52-8] (91) (Cl Disperse Red 1 Cl 11110). 

Terephthalic acid has been obtained from a great many /)-disubstituted derivatives of benzene or cyclohexane by oxidation with permanganate, chromic acid, or nitric acid. The following routes appear to have preparative value from />-toluic acid, />-methylacetophenone,2 or dihydro-/)-tolualdehyde by oxidation with permanganate from f>-cymene by oxidation with sodium dichromate and sulfuric acid from />-dibromobenzene or from /i-chloro- or -bromobenzoic acid by heating at 250° with potassium and cuprous cyanides and from />-dibromo-benzene, butyllithium, and carbon dioxide. ... 

Phenol An organic compound that is an alcohol derivative of benzene. 

Some derivatives of benzene can be fluorinated over cobalt trifluoride at lower temperatures. At 125 °C, 2H-tetrafluoronitrobenzene gives irans-2H,] -ni-trodecafluorocyclohexane, ci5-2ff, 1-nitrodecafluorocyclohexane, trans-5H,4-ni-... 

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