Kinetics of reactions in heterocycles. Part II. Replacement of the methylsulphonyl group in substituted pyridines, pyridazines, and pyrazine by methoxide ion

Abstract

Kinetic study of the reactions of methylsulphonylpyridines, pyridazines, and pyrazine with methoxide ion shows that the methylsulphonyl group is very readily replaced. Where direct comparison is possible, as in the 3-substituted pyridazines, it is found that the methylsulphonyl compound is ca. 90 times more reactive than the chloro-compound, at 40·2°.

The preparation of new methylsulphonyl compounds is described. Ionisation constants and ultraviolet and nuclear magnetic resonance spectra are recorded and discussed.