Nitro, acids alkyl benzenes

Oxidation of side chains. Aromatic nitro compounds that contain a side chain (e.g., nitro derivatives of alkyl benzenes) may be oxidised to the corresponding acids either by alkahne potassium permanganate (Section IV,9, 6) or, preferably, with a sodium dichromate - sulphuric acid mixture in which medium the nitro compound is more soluble. 

Oxidation of an alkylated benzene (making an aryl carboxylic acid) is a method of converting an ortho-para activator into a meta director. The reduction of a nitro group to make an aryl amine is a way of changing a meta director into an ortho-para activator. 

In Chapter 15, you learned how to prepare benzene rings with halo, nitro, sulfonic acid, alkyl, and acyl substituents. 

Benzene rings with substituents other than halo, nitro, sulfonic acid, alkyl, and acyl can be prepared by first synthesizing one of these substituted benzenes and then chemically changing the substituent. The kinds of substituents that can be placed on benzene rings are greatly expanded by reactions of arene dia-zonium salts, nucleophilic aromatic substitution reactions, and reactions involving a benzyne intermediate. The relative positions of two substituents on a benzene ring are indicated either by numbers or by the prefixes ortho, meta, and para. 

Virtually all nitration reactions involve electrophillic attack by nitronium ions, NO2. Consequently, reactions can be regulated by controlling the concentration of nitronium ions in solution. The conditions required for the nitration reaction vary greatly with the reactivity of the aromatic substrate. The nitration mixture required for introduction of the second nitro group into benzene to prepare dinitrobenzene and concentrated nitric and sulfuric acids at 95°C is unsuitable for dinitration of alkylated phenol because it provides the conditions for an uncontrollable exothermic reaction. The DNBP process described above was based on controlling the nitration conditions and has the advantage of having very few side reactions because it is a two-phase system with nitration reactivity based on mass transfer between phases. 

Nitro compounds may be photoreduced by suitable hydrogen donors under sunlight. For example, nitrobenzene was reduced by toluene to yield aniline, 4-amino phenol, azoxy benzene, and benzoic acid. Alkyl aromatics that can form benzyl-type radicals were efficient hydrogen donors for this reaction. The sorption of nitrobenzene to humus with increased residence time and reaction sites will likely make this pathway play a significant role in the fate of nitrobenzene. Half-life of toluene calculated from smog chamber experi-... 

Amine, Alcohol, Aldehyde, Alkane, Alkene, Alkyl Halide, Alkyne, Carboxylic Acid, Epoxide, Ether, Ketone, Nitrile (cyano), Nitro, Phenyl Group (benzene ring) and Thiol. 

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