Reactions of N-heteroaromatic bases with nitrous acid. Part III. Kinetics of diazotisation of 2-aminopyridine

Abstract

The kinetics of diazotisation of 2-aminopyridine have been studied in 0·0025–5·0M-perchloric acid. The results suggest that the reaction takes place by one mechanism only. The kinetic form obtained is of the first order in both the amine and nitrous acid. The rate of the reaction shows an exponential catalytic dependence on the concentration of perchloric acid. It also shows a rather small exponential dependence on the concentration of added sodium perchlorate. In perchloric acid solutions the dependence of the rate of the reaction on the H₀ function is only slightly greater than linear, whilst in perchloric acid solutions whose ionic strength is maintained constant by the addition of sodium perchlorate there is an almost linear correlation. The effect of the ionic strength of the medium on the diazotisation of 2-aminopyridine as manifested by the influence of sodium perchlorate is smaller than the effect on the diazotisation of 4-aminopyridine.