Coulometric titration of anilines, mainly containing deactivating functional groups, with bromine.
A general method is described for the coulometric titration of various substituted anilines with anodically generated bromine. The reaction is carried out in water-acetic acid medium and the reactivity is governed by varying the water content and the bromide concentration, and by the addition of pyridine. In this way the majority of the substituted anilines tested can be titrated quantitatively. There is no great difference in the reactivity-promoting properties of pyridine-free and pyridine-containing media, but the latter generally give the better results and are therefore to be preferred. The mean relative error, for the best medium for each compound, is +/-0.5% for the haloanilines and +/-1.0% for anilines with oxygenated functional groups.
Truedsson
L A
LA
Department of Technical Analytical Chemistry, Chemical Center, Lund, Sweden.