Synthesis and acid-base transformations of (4-styrylpyridinio)-alkanesulfonates

(4-Styrylpyridinio)alkanesulfonates were synthesized by condensation of 2-(4-methylpyridinio)- and 2-(4-ethylpyridinio)-1-ethanesulfonates with aromatic aldehydes, and also by quaternization of 4-styrylpyridine by sulfoalkylating agents. For the p- and o-hydroxystyrylpyridinium compounds in aqueous solutions, the pK_a values were determined spectrophotometrically. It is believed that the planarity of the o-hydroxypyridinium compounds is disturbed because of the reaction of the hydroxy and the -sulfonatomethyl groups.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1357–1362, October, 1986.