Chlorination aniline

The fate of dissolved amines during disinfection of water by chlorination was determined by membrane injection MS. Aliphatic amines undergo TV-chlorination to exhaustion of the N-H atoms by one of the tentatively proposed paths shown in reaction 28. Aromatic amines undergo mainly ring substitution however, the possible intervention of N-C1 intermediates is not excluded. At pH 10.6 aniline chlorination is much slower than that of n-butylamine383. 

Figure 10.35 MBT feedstock is produced from carbon disulfide and aniline Chlorine is obtained as follows in Figure 10.36.

Hydrolysed by dilute acids and alkalis to aniline. It chlorinates more slowly than aniline to o-and p-chloroacetanilides. 

There are two sequences in which the reaction can be carried out. For most anilines the first step is /V-chlorination which can be done with t-butyl hypochlorite[9]. However, for anilines with ER substituents it may be preferable to halogenate the thioester. The halogenation can be done with Cl2[lbl or SOjCljCU]. For some anilines simply adding f-butyl hypochlorite to a mixture of the aniline and thioester is satisfactory (Entries 1, 4, Table 7.6). 

Halogenation. The presence of the amino group activates the ortho and para positions of the aromatic ring and, as a result, aniline reacts readily with bromine or chlorine. Under mild conditions, bromination yields 2,4,6-trihromoaniline [147-82-0]. 

Chlorine in the presence of hydrogen chloride in an anhydrous organic solvent yields 2,4,6-trichloroariiline [634-93-5] (36,37). A mixture of aniline vapor and chlorine, diluted with an inert gas, over activated carbon at 400°C yields o-chloroaruline [95-51-2] (38). Aniline when treated with chlorine gas, in an aqueous mixture of sulfuric acid and acetic acid, at 105—115°C gives an 85—95% yield of -chlorarul [118-75-2] (39). 

Nitration of benzene yields nitrobenzene, which is reduced to aniline, an important intermediate for dyes and pharmaceuticals. Benzene is chlorinated to produce chlorobenzene, which finds use in the preparation of pesticides, solvents, and dyes. 

Chlorocarbons and Chlorohydrocarbons-Dichloroethylenes" under "Chlorine Compounds, Organic", in ECT 1st ed., VoL 3, pp. 786—787, byj. Werner, General Aniline Film Corp., Aniline Works Division "Chlorocarbons and Chlorohydrocarbons-Dichloroethylenes" in ECT 2nd ed., VoL 5, pp. 178—183, by D. W. F. Hardie, Imperial Chemical Industries, Ltd "1,2-Dichloroethylene" under "Chlorocarbons, -Hydrocarbons" in ECT 3rd ed., Vol. 5, pp. 

The chlorobenzene operations in the United States were developed primarily for the manufacture of phenol, aniline, and DDT. However, with the process changes in the production of phenol and aniline, the phase-out of DDT production, and changes in the herbicide and solvent markets, the U.S. production of chlorinated benzenes has shmnk by more than 50% since the total production peaked in 1969. U.S. production of monochlorobenzene peaked in the 1960s and decreased to a low of 101 million kg in 1986 with an 11% and 9% increase, respectively, in 1988 and 1989. 

Sandmeyer Reaction. This general reaction allows the phenol function to be introduced. The technique complements chlorination insofar as it makes it possible to produce chlorophenols chloriaated in the meta position from the corresponding meta-chlotinated anilines. 

The amine hydrogens of polyfluorinated anilines can be replaced with chlorine by using tert-butyl hypochlorite [65,66]... 

A solution to the question of the mechanism of these reactions was provided by John D. Roberts in 1953 on the basis of an imaginative experiment. Roberts prepared a sample of chlorobenzene in which one of the car bons, the one bearing the chlorine, was the radioactive mass-14 isotope of carbon. Reaction with potassium amide in liquid fflnmonia yielded aniline containing almost exactly half of its label at C-1 and half at C-2 ... 

The electronic properties of the aniline are important in the Doebner reaction. The reaction works best with electronic donating groups. Anilines substituted with a chlorine at the meta position consistently give low yields, but fluorine at the meta position seems... 

Finally, with compounds of type 7, which have one chlorine atom and two ZR substituents, the reactions are, as expected, more frequently acid catalyzed than with compounds of type 6 e.g., the reaction with aniline in acetone is distinctly acid catalyzed. Again, reactions stiU occur, e.g., with benzylamine in tetrahydrofuran, in which autocatalysis is absent, possibly because of a combination of the marked basicity of the reagent and the low solubility of the acidic product. 

In hydroxyUc solvents, the reaction with aniline follows a bi-molecular course but is complicated by competing solvolysis. This is a striking result when compared with the behavior of picryl chloride, which is much more selective with regard to the same reagents (aniline and alcohol), and has been interpreted to mean that bond-breaking has made appreciable progress in the rate-determining step of the reaction of phosphonitrilic chloride. Furthermore, the same indication is obtained from the fact that in the reactions of the halides, the fluorine chlorine ratios are less than one. ... 

QuinoxaIin-2-oncs are readily converted into the corresponding 2-chloroquinoxalines by treatment with phosphoryl chloride in the case of the highly insoluble 2,3-diones chlorination is effected conveniently with a mixture of phosphoryl chloride and dimethyl-aniline. The use of phosphorus pcntachloride may lead to side reactions, for example, quinoxalin-2-one (70) is converted into 2,3-... 

Condensation of normeperidine (81) with 3-chloropropan-l-ol affords the compound possessing the alcohol side chain (88). The hydroxyl is then converted to chlorine by means of thionyl chloride (89) displacement of the halogen by aniline yields pimino-dine (90). ° Condensation of the secondary amine, 81, with styrene oxide affords the alcohol, 91 removal of the benzyllic hydroxyl group by hydrogenolysis leads to pheneridlne (92). ... 

The usual range of film coefficient values is 40-50 for organic solvents and light petroleum fractions such as hexanes 25 for heavier materials such as aniline, straw oil, etc. and 0.5-3 for low temperature (10-40°F) subcooling of heavier organics and inorganics such as chlorine. 

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