Some Comments on the Preparation of Amines

Therefore, it is possible to utilize the corresponding protonated amines to define basicity. 

Finally, it has recently been pointed out that With a production on million-ton scale per year, aliphatic amines are among the important bulk and fine chemicals in the chemical and pharmaceutical industry. A number of amines, enamines, and imines are useful as pharmaceutically and biologically active substances, dyes, and fine chemicals.  

Methods for the preparation of such compounds continue to be developed and will be considered as a part of the material in this chapter. 

It will be recalled that methane (CH4) can be converted to nitromethane (H3CNO2) by the action of nitric acid on methane at high temperature (Chapter 6, Equation 6.10). The nitration of other alkanes by the same process can also be effected, but separation of the multitude of isomers that can be formed (from all but the simplest alkanes) can be difficult. Nitroalkanes, R-NO2 (sometimes accompanied by their corresponding nitrite isomers, R-ONO), can also be prepared (as shown in Chapter 7, Table 7.5e) by treatment of alkyl halides with nitrite anion (ONO ). Reduction of nitroalkanes (R-NO2) with hydrogen (H2) in the presence of a platinum (Pt) catalyst or lithium aluminum hydride (LiAIlT,) in ether produces the corresponding amine (Equation 10.18). 

Although, generally, production of aminobenzene (aniline) and related N-arylamines by nitration and subsequent reduction is so common as to far outweigh other methods of formation of such compounds, special circumstances (such as a need to avoid the acidic conditions normally associated with nitronium ion [N02 ] formation) occasionally prevail and alternative methods need to be used. 

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