Aryl halides ammonolysis

Ammonolysis of aryl halides has been performed under PTC conditions.125 The reaction of 2,4-dinitro-chlorobenzene with NH3 (g) in toluene at ambient temperature and pressure gave, in the presence of 10% TBAB and after 3 h, 2,4-dinitroaniline in 16% yield (0.6% in the absence of TBAB). The reaction was complete after 24 h but the product final yield was not reported.125... 

Ammonolysis of halides is usually limited to the aliphatic series, because of the generally low reactivity of aryl halides toward nucleophilic substitution. (However, see Chap. 25.) Ammonolysis has the disadvantage of yielding a mixture of different classes of amines. It is important to us as one of the most general methods of introducing the amino ( NH2) group into molecules of all kinds it can be used, for example, to convert bromoacids into amino acids. The exactly analogous reaction of halides with amines permits the preparation of every class of amine (as well as quaternary ammonium salts, R4N X ). 

If secondary and tertiary amines are desired, only 2 to 3 moles of ammonia are used. Aqueous ammonia does not react to any extent at room temperature, owing to the immiscibility of halide and water. Industrially, aqueous ammonia is used and heated in an autoclave under pressure. Tertiary halides, as, for example, tert-butyl and tert- m.y bromides, do not yield amines, but yield olefines almost exclusively. The object of the present experiment is to illustrate the ammonolysis of alkyl halides. The ammonolysis of aryl halides cannot be easily accomplished in the laboratory, as it involves the use of high pressure, and temperatures of about 200°. Industrially the method is practical. 

There is a dearth of information regarding the efficacy of emulsifying and wetting agents in the amination process. Such agents appear to have important potential utility in the ammonolysis of aryl halides such as... 

Partial ammonolysis of phosphorus(V) chloride or bromide and of monoalkyl- or -aryl-substituted dichloro- or dibromophos-phines in the presence of chlorine or bromine is a general method for the synthesis, respectively, of the corresponding simple or substituted phosphonitrile halides. " This type of reaction may yield either cyclic or linear poljuners, depending upon the temperature, solvent, reaction time, and/or reagent ratio. 

Ammonolysis of aromatic halides, however, may lead to unexpected products. For example, Gilman and Martin report that aryl ethers, thio ethers, and sulfones with ortho-halogen substituents rearrange to metarsubstituted anilines when treated with sodamide in liquid NH3. 

Acylfurans, ammonolysis, 665 frcm acylation of furans, 665 2-fnroyl halides, 665 used in synthesis of 2-alkyl (aryl)-3-pyridinols, 665 N-acylpyridones, rearrangement, 776... 

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