A general method for coulometric titration of alkylanilines with bromine

A general method is described for the coulometric titration of alkylanilines 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 concentration of bromide ion and by the addition of pyridine. In this way most types of alkylanilines can be titrated quantitatively. Unlike the case for alkylphenols, the bromine consumption is not always higher in the pyridine-containing media than in the pyridine-free. The bromine consumption is also more dependent on the bromide content of the medium than it is for alkylphenols. The mean relative error, for the best medium for each compound, is +/-0.9% for primary alkylanilines, +/-0.9% for secondary and +/-1.2% for tertiary.