Benzenamine aromaticity

Synonyms AI3-03053 Aminobenzene Aminophen Aniline oil ANL Anyvim Aromatic amine Arylamine Benzenamine Benzidam Blue oil BRN 0605631 Caswell No. 051C CCRIS 44 C.I. 76000 C.l. oxidation base 1 Cyanol EINECS 200-539-3 EPA pesticide chemical code 251400 Krystallin Kyanol NCI-C03736 Phenylamine RCRA waste number U012 UN 1547. 

Aromatic and cyclic amines often have common names such as aniline (benzenamine), Cf,H5NH2 p-toluidine, p-CH,C(,H4NH2 and piperidine [Problem 18.1(g)]. 

Alkenamines, or enamines, R—CH=CHNH2, usually are not stable and rearrange readily to imines (Section 16-4C). An important exception is benzenamine (aniline), C6H5NH2, which has an amino group attached to a benzene ring. The imine structure is less favorable by virtue of the considerable stabilization energy of the aromatic ring ... 

Alkanamines have acid strengths corresponding to Ka values of about 10 33, which means that their conjugate bases are powerfully basic reagents. Therefore they are very effective in causing elimination reactions by the E2 mechanism (Section 8-8) and aromatic substitution by the aryne mechanism (Section 14-6C). The following example illustrates this property in a useful synthesis of a benzenamine from bromobenzene ... 

Aromatic amines fall into two categories those in which the amino group is directly attached to the aromatic ring and those where an amino group is part of a side chain. This chapter concentrates on the former group and deals with compounds such as aniline (phenylamine, benzenamine 1), rather than benzylamine (phenylmethanamine, 2) and similar compounds in which the amino group exhibits the reactions of an aliphatic amine. 

Poly(imides) contain the group -C(0)-NH-C(0)- in their structure. Many poly(imides) with practical applications have a more complicated formula and contain oxygen atoms and aromatic rings in the backbone [1]. One example is poly(pyromellitic dianhydride-a/f-4,4 -oxydianiline) or PMDA-ODA, CAS 25038-81-7, which is obtained from pyromellitic anhydride and oxybis(benzenamine) by water elimination as follows ... 

Several aromatic amines have special names that have also been approved for use by I.U.P.A.C. For example, the amine of benzene is given the name aniline. In the CA system, aniline is named benzenamine. 

Claisen-Schmidt condensation, 720, 728 with methylamine, 673, 873 nitration, 467, 873 reductive amination, 881 with vinyllithium, 556 Benzenamine, 859. See also Aniline Benzene, 54, 399-406, 433 34 acidity of, 552, 577 Birch reduction of, 413-414 derivatives, nomenclature of, 406-408 electrophilic aromatic substitution in,... 

Aniline (benzenamine) [62-53-3] is the simplest of the primary aromatic amines. It was first produced in 1826 by dry distillation of indigo. In 1840 the same oily hquid was obtained by heating indigo with potash, and it was given the name aniline. The stmcture of aniline was estabUshed in 1843 with the demonstration that it could be obtained by reduction of nitrobenzene. 

Synonyms Anilinomethane Benzenamine, N-methyl- (Methylamino) benzene N-Methylaminobenzene Methylaniline N-Methylbenzenamine Methylphenylamine N-Methylphenylamine Monomethyl aniline N-Monomethylaniline N-Phenylmethylamine Ciassification Aromatic sec. amine Empiricai C7H9N Formuia CeHsNHCHa... 

Aromatic amines are nsed mainly in the manufacture of dyes. Benzenamine (aniline), the simplest aromatic amine, is a toxic compound a number of other aromatic amines such as 2-naphthylamine and benzidine are potent carcinogens ... 

Aromatic nitration is the best way to introduce nitrogen-containing substituents into the benzene ring. The nitro group functions as a directing group in further substitutions (Chapter 16) and as a masked amino function (Section 16-5), as unraveled in benzenamines (anilines Section 22-10). 

ANIMATED MECHANISM Electrophilic aromatic substitution of benzenamine (ortho vs meta vs para)... 

The aromatic amines, or anilines, are called benzenamines (Section 15-1). For secondary and tertiary anunes, the largest alkyl substituent on nitrogen is chosen as the alkanamine stem, and the other groups are named by using the letter N-, followed by the name of the additional substituent(s). 

Amines react with nitrous acid, through nucleophilic attack on the nitrosyl cation, NO. The product depends very much on whether the reactant is an alkanamine or a benzenamine (aniline) and on whether it is primary, secondary, or tertiary. This section deals with alkanamines aromatic amines will be considered in the next chapter. 

As mentioned in Section 22-4, V-nitrosation of primary benzenamines (anilines) furnishes arenediazonium salts, which can be used in the synthesis of phenols. Arenediazonium salts are stabilized by resonance of the tt electrons in the diazo function with those of the aromatic ring. They are converted into haloarenes, arenecarbonitriles, and other aromatic derivatives through replacement of nitrogen by the appropriate nucleophile. 

A series of new 5,6-dihydro-indolo[l,2-a]quinoxaline derivatives 533 has been prepared in moderate to excellent yields from 2-(indol-l-yl)benzenamines 532 with aromatic aldehydes 252a, d, e, h-j by an efficient and economical iron-catalyzed Pictet-Spengler reaction (Scheme 2.126) (Xu and Fan 2011). 

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