Chloronitrobenzene ammonolysis

The ammonolysis of aromatic halides follows a pattern similar to the esters. For example, substituted chloronitrobenzenes containing a la-bilized chlorine atom react in aqueous ammonia at a rate proportional to the concentration of both reactants—indicating that the mechanism is second order. ... 

Continuous Preparation of Nitroanilines. The I.G. Farbenindustrie developed a continuous process for the ammonolysis of o-chloronitroben-zene, p-chloronitrobenzene, 2,5-dichloronitrobenzene, and 3,4-dichloronitro-benzene to o-nitro-, p-nitro-, 4-chloro-2-nitro-, and 2-chloro-4-nitroanilines, respectively. The facilities are shown diagrammatically in simplified form in Fig. 8-23. 

Most derivatives of aniline are not obtained from aniline itself, but are prepared by hydrogenation of their nitroaromatic precursors. The exceptions, for example, N-alkylanilines, N-arylanilines, sulfonated anilines, or the N-acyl derivatives, can be prepared from aniline and have been discussed. Nitroanilines are usually prepared by ammonolysis of the corresponding chloronitrobenzene. Special isolation methods may be required for some derivatives if the boiling points are close and separation by distillation is not feasible. Table 6 Hsts some of the derivatives of aniline that are produced commercially. 

Figure 5.46 shows the flow diagram for ammonolysis of chloronitrobenzene to nitroaniline. 

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