ON THE TRANSFORMATION OF AROMATIC NITROAMINES. 103 
(iii) No transformation occurs in aqueous solution when the con- 
centration of the transforming agent is below a certain value (for hydro- 
chloric acid below N/200), the nitroamine being at a dilution of V=207. 
The additive compound is apparently completely ‘hydrolysed’ at such 
dilution. 
(iv) The additive compound is not formed from gaseous hydrogen 
chloride and the nitroamine when the pressure of the former is below a 
certain yalue—namely, the dissociation pressure of the compound. This 
pressure is approximately 1/30 atmosphere at 15° C. 
It has been suggested! that the additive compound of the nitroamine 
and the transforming agent is alone capable of undergoing those further 
changes, probably through the transitory conversion «of the, benzene 
nucleus into a quinonoid form, by which the nitro-group ‘wanders’ from 
the nitrogen into the nucleus, whereas the simple nitroamine has no such 
power. 
Il. The Wandering of Bromine in the Chlorination of Bromoanilines. 
(With W. W. Ruzp, B.Sc.) 
Although the replacement of bromine by chlorine in ani'ines? and in 
bromobenzenediazonium chlorides* has been observed, the displacement 
of bromine by chlorine from a given position in the benzene nucleus, 
’ followed, however, by a subsequent re-entry in another position, has not 
been described. 
In the chlorination of p-bromoaniline, either by the usual method of 
passing chlorine into a solution in benzene or chloroform, or by the more 
delicate procedure of adding the requisite quantity of a solution of 
chlorine, or, finally, by using solutions of the aniline and chlorine (in the 
correct proportions, C;H,Br.NH,/2Cl,) in 20 per cent. hydrochloric 
acid, the expected 2 : 6-dichloro-4-bromoaniline 
is not alone obtained. It is always mixed with 2 : 4-dibromo-6-chloro- 
and s-trichloro-anilines, and cannot be separated from them. The aniline 
can, however, be prepared in a pure state by indirect chlorination of the 
p-bromoaniline in chloroform solution with a solution of 2 : 4-dichloro- 
acetylchloraminebenzene in the same solvent, thus : 
C,H,Br . NH, + 20,H,Cl,. NC]. AC =(,H,Cl,Br . NH, + 20,H,CI,. NH. AC 
Under these conditions displacement of bromine does not occur. 
Similar results were obtained by chlorinating 2 : 4-dibromoaniline 
in hydrochloric acid solution. On subjecting o-bromo, m-bromo, or 
2: 6-dibromo-aniline to a similar treatment no such displacement was 
observed, each substance yielding a single chloro-derivative. 
1 Orton, Proc. Roy. Soc., 1901, 71, 153. 
ae * Wegscheiden, Monatsheft, 18, 329; Chattaway and Orton, Trans. Chem. Soc., 
, 822 
* Hantzsch, Berichte d. Chem. Gesell., 30, 2334. 
