Phenyl ring substituted aniline

Molecular complexes between substituted anilines and some hydroperoxides are mainly due to the OOH N hydrogen bonding interaction, as tested by infrared absorption spectral data121. In CCI4 solution there is evidence for the presence of both O—H N and O H—N interactions. The predominance of one of these types of interaction is affected by the structure of the hydroperoxide and by the substituent bonded to the phenyl ring of aniline. The high acidity of some hydroperoxides, such as 1,1-diphenylhydroperoxide and a-cumyl hydroperoxide, is responsible for the salt character of the formed N+—H O ion pair. 

Steric effects on the nucleophile, aniline, were clearly evident. Rate constants for bimolecular attack of 2,6-dimethyl- 70a, 2,6-diethyl- 70b, and 3,5-dimethylaniline 70c at 308 K indicate that the ort/zo-substituted anilines react more than an order of magnitude slower at the same temperature (Table 7). Structure 70c must be able approach the reactive nitrogen more closely.42,43 A comparison of the rate constants for reaction of aniline 72c, /V-methyl- 71a and /V-phenylaniline 71b provides further evidence of steric effects although the very small rate constant for the diphenylamine could also be accounted for by reduced nucleophilicity on account of lone pair resonance into the additional phenyl ring. 

These addition reactions require formation of an imino-cyclohexadiene intermediate (Fig. 13.41). In cases where the ipso substituent is a proton, tautomeriza-tion to form the substituted aniline derivative is fast, and such intermediates have not been isolated. On the other hand, in situations where the nucleophile adds to a substituted ring position, the intermediate can undergo further secondary reactions. For example Novak et al. showed that the 4-biphenylylnitrenium ion reacts with water forming the imine cyclohexadiene intermediate 74, which in turn experiences an acid-catalyzed phenyl shift reaction to 76 via 75 (Fig. 13.42). 

The procedure described here is based on a method outlined in U. S. patent 2,444,536.2 N-Phenylmaleimide has also been prepared by the dry distillation of the aniline salt of malic acid, 4 by treating the aniline salt of malic acid with phosphorus pent-oxide,5 and by treating maleanilic acid with phosphorus trichloride or with phosphorus pentoxide.5 Ring-substituted N-phenylmaleimides, viz., N-(/>-methoxyphenyl)-, N-(p-ethoxy-phenyl)-, and N-(/>-nitrophenyl)maleimide, have been prepared by treatment of the appropriate maleanilic acids with acetic anhydride and fused potassium acetate.7... 

Substituted PANIs (polymers of functionalize aniline molecules), on the other hand, have also become an alternative choice to obtaining the desired properties of processability and solubility. For example, the polymerization of a derivatised aniline such as 2-methoxyaniline, results in a soluble conducting polymer. In general, substituent groups present in the units of the polymer chain cause decrease in the stiffness of the polymer chain to result in better solubility. Unfortunately such improvements by substitution of groups in the phenyl ring or A -position of polyaniline units are also accompanied by decrease of conductivity. Nevertheless, aniline substituted with two methoxy groups, 2,5-dimethoxyaniline, has been reported to contrarily produce a soluble polymer, poly(2,5-dimethoxyaniline), PDMA, with a conductivity similar to PANI [57]. 

SCHEME 2. Structures of some substituted anilines with two separated phenyl rings... 

One of the most general and frequently applied indirect methods is the transformation of an organic compound into a nitrocompound. The method is applied to hydrocarbons and other aromatic compounds, mainly those bearing a phenyl ring, e.g. phenols, substituted anilines, phenyl-bearing amino acids etc. The nitrating mixture consists of nitric acid, either pure or... 

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